Monday, June 17, 2019

Number of the day: 245158254

Properties of the number 245158254:

245158254 = 2 × 32 × 11 × 19 × 65167 is the 231729379th composite number and is not squarefree.
245158254 has 5 distinct prime factors, 48 divisors, 29 antidivisors and 70379280 totatives.
245158254 has a triangular digit sum 36 in base 10.
245158254 = 2383 + 2853 + 5933 is the sum of 3 positive cubes in 1 way.
245158254 is the difference of 2 positive pentagonal numbers in 4 ways.
245158254 = 502 + 2772 + 156552 is the sum of 3 positive squares.
2451582542 is the sum of 3 positive squares.
245158254 is a proper divisor of 68321722 - 1.
245158254 = '24515' + '8254' is the concatenation of 2 semiprime numbers.

Sunday, June 16, 2019

Number of the day: 5328

Properties of the number 5328:

5328 = 24 × 32 × 37 is the 4622th composite number and is not squarefree.
5328 has 3 distinct prime factors, 30 divisors, 7 antidivisors and 1728 totatives.
5328 has an oblong digit product 240 in base 10.
5328 is the difference of 2 nonnegative squares in 9 ways.
5328 is the sum of 2 positive triangular numbers.
5328 is the difference of 2 positive pentagonal numbers in 1 way.
5328 = 122 + 722 is the sum of 2 positive squares in 1 way.
5328 = 162 + 442 + 562 is the sum of 3 positive squares.
53282 = 17282 + 50402 is the sum of 2 positive squares in 1 way.
53282 is the sum of 3 positive squares.
5328 is a proper divisor of 732 - 1.
5328 is palindromic in (at least) the following bases: 11, and 73.
5328 in base 6 = 40400 and consists of only the digits '0' and '4'.
5328 in base 11 = 4004 and consists of only the digits '0' and '4'.
5328 in base 17 = 1177 and consists of only the digits '1' and '7'.
5328 in base 19 = ee8 and consists of only the digits '8' and 'e'.
5328 in base 36 = 440 and consists of only the digits '0' and '4'.
5328 in base 51 = 22O and consists of only the digits '2' and 'O'.

The number 5328 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A033996: 8 times triangular numbers: a(n) = 4*n*(n+1).
A084920: a(n) = (prime(n)-1)*(prime(n)+1).
A106302: Period of the Fibonacci 3-step sequence A000073 mod prime(n).
A173116: a(n) = sinh(2*arcsinh(n))^2 = 4*n^2*(n^2 + 1).
A179669: Products of form p^4*q^2*r where p, q and r are three distinct primes.
A236278: T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the upper median unequal to the lower median in every 2X2 subblock
A247726: T(n,k)=Number of length n+3 0..k arrays with no disjoint pairs in any consecutive four terms having the same sum
A248925: Triangle in which row n consists of the coefficients in Sum_{m=0..n} x^m * Product_{k=m+1..n} (1-k*x), as read by rows.
A257368: Numbers n such that the decimal expansions of both n and n^2 have 2 as smallest digit and 8 as largest digit.
A317707: Number of powerful rooted trees with n nodes.

Thursday, June 13, 2019

Number of the day: 286345

John Forbes Nash, Jr. was born on this day 91 years ago.

Properties of the number 286345:

286345 is a cyclic number.
286345 = 5 × 57269 is semiprime and squarefree.
286345 has 2 distinct prime factors, 4 divisors, 11 antidivisors and 229072 totatives.
286345 has a triangular digit sum 28 in base 10.
Reversing the decimal digits of 286345 results in an emirpimes.
286345 = 1431732 - 1431722 = 286372 - 286322 is the difference of 2 nonnegative squares in 2 ways.
286345 is the sum of 2 positive triangular numbers.
286345 is the difference of 2 positive pentagonal numbers in 2 ways.
286345 = 2882 + 4512 = 1882 + 5012 is the sum of 2 positive squares in 2 ways.
286345 = 442 + 752 + 5282 is the sum of 3 positive squares.
2863452 = 1883762 + 2156572 = 1718072 + 2290762 = 1204572 + 2597762 = 595002 + 2800952 is the sum of 2 positive squares in 4 ways.
2863452 is the sum of 3 positive squares.
286345 is a proper divisor of 1429278 - 1.
286345 = '286' + '345' is the concatenation of 2 sphenic numbers.
286345 is an emirpimes in (at least) the following bases: 2, 10, 22, 25, 28, 29, 37, 38, 41, 43, 48, 52, 55, 57, 60, 63, 65, 67, 71, 72, 73, 77, 82, 91, 92, 93, and 99.

Wednesday, June 12, 2019

Number of the day: 712398

Vladimir Igorevich Arnold was born on this day 82 years ago.

Properties of the number 712398:

712398 = 2 × 3 × 37 × 3209 is the 654913th composite number and is squarefree.
712398 has 4 distinct prime factors, 16 divisors, 15 antidivisors and 230976 totatives.
712398 has a sphenic digit sum 30 in base 10.
712398 has an oblong digit sum 30 in base 10.
712398 is the sum of 2 positive triangular numbers.
712398 is the difference of 2 positive pentagonal numbers in 4 ways.
712398 = 172 + 1222 + 8352 is the sum of 3 positive squares.
7123982 = 4706402 + 5347982 = 3532502 + 6186482 = 2717522 + 6585302 = 2310482 + 6738902 is the sum of 2 positive squares in 4 ways.
7123982 is the sum of 3 positive squares.
712398 is a proper divisor of 102172 - 1.
712398 is palindromic in (at least) base -96.

Tuesday, June 11, 2019

Number of the day: 771577455

Properties of the number 771577455:

771577455 = 3 × 5 × 11 × 4676227 is the 731819308th composite number and is squarefree.
771577455 has 4 distinct prime factors, 16 divisors, 19 antidivisors and 374098080 totatives.
Reversing the decimal digits of 771577455 results in a sphenic number.
771577455 = 3857887282 - 3857887272 = 1285962442 - 1285962412 = 771577482 - 771577432 = 350717082 - 350716972 = 257192562 - 257192412 = 116905842 - 116905512 = 70143682 - 70143132 = 23381962 - 23380312 is the difference of 2 nonnegative squares in 8 ways.
771577455 is the difference of 2 positive pentagonal numbers in 4 ways.
771577455 is not the sum of 3 positive squares.
7715774552 = 4629464732 + 6172619642 is the sum of 2 positive squares in 1 way.
7715774552 is the sum of 3 positive squares.
771577455 is a proper divisor of 199150846 - 1.

Monday, June 10, 2019

Number of the day: 264666435

Properties of the number 264666435:

264666435 = 3 × 5 × 11 × 223 × 7193 is the 250229848th composite number and is squarefree.
264666435 has 5 distinct prime factors, 32 divisors, 35 antidivisors and 127729920 totatives.
264666435 has a sphenic digit sum 42 in base 10.
264666435 has an oblong digit sum 42 in base 10.
264666435 is the difference of 2 nonnegative squares in 16 ways.
264666435 is the difference of 2 positive pentagonal numbers in 7 ways.
264666435 = 4272 + 8452 + 162412 is the sum of 3 positive squares.
2646664352 = 1012892762 + 2445174932 = 656790752 + 2563875602 = 1657026032 + 2063757962 = 1587998612 + 2117331482 is the sum of 2 positive squares in 4 ways.
2646664352 is the sum of 3 positive squares.
264666435 is a proper divisor of 967444 - 1.
264666435 = '264666' + '435' is the concatenation of 2 sphenic numbers.

Sunday, June 9, 2019

Number of the day: 791708

John Edensor Littlewood was born on this day 134 years ago.

Properties of the number 791708:

791708 = 22 × 197927 is the 728373th composite number and is not squarefree.
791708 has 2 distinct prime factors, 6 divisors, 33 antidivisors and 395852 totatives.
Reversing the decimal digits of 791708 results in a prime.
791708 = 1979282 - 1979262 is the difference of 2 nonnegative squares in 1 way.
791708 is the difference of 2 positive pentagonal numbers in 1 way.
791708 is not the sum of 3 positive squares.
7917082 is the sum of 3 positive squares.
791708 is a proper divisor of 1798963 - 1.
791708 is palindromic in (at least) base -93.

Saturday, June 8, 2019

Number of the day: 80997

Properties of the number 80997:

80997 = 3 × 72 × 19 × 29 is the 73071th composite number and is not squarefree.
80997 has 4 distinct prime factors, 24 divisors, 35 antidivisors and 42336 totatives.
80997 has a semiprime digit sum 33 in base 10.
80997 is the difference of 2 nonnegative squares in 12 ways.
80997 is the sum of 2 positive triangular numbers.
80997 is the difference of 2 positive pentagonal numbers in 4 ways.
80997 = 172 + 822 + 2722 is the sum of 3 positive squares.
809972 = 558602 + 586532 is the sum of 2 positive squares in 1 way.
809972 is the sum of 3 positive squares.
80997 is a proper divisor of 5216 - 1.
80997 = '809' + '97' is the concatenation of 2 prime numbers.
80997 in base 34 = 2229 and consists of only the digits '2' and '9'.

Friday, June 7, 2019

Number of the day: 763132

Properties of the number 763132:

763132 = 22 × 190783 is the 701917th composite number and is not squarefree.
763132 has 2 distinct prime factors, 6 divisors, 23 antidivisors and 381564 totatives.
763132 has a semiprime digit sum 22 in base 10.
763132 has an oblong digit product 756 in base 10.
Reversing the decimal digits of 763132 results in a prime.
763132 = 1907842 - 1907822 is the difference of 2 nonnegative squares in 1 way.
763132 is the sum of 2 positive triangular numbers.
763132 is the difference of 2 positive pentagonal numbers in 1 way.
763132 is not the sum of 3 positive squares.
7631322 is the sum of 3 positive squares.
763132 is a proper divisor of 6013533 - 1.

Thursday, June 6, 2019

Number of the day: 2307484

Aleksandr Mikhailovich Lyapunov was born on this day 162 years ago.

Properties of the number 2307484:

2307484 = 22 × 733 × 787 is the 2137465th composite number and is not squarefree.
2307484 has 3 distinct prime factors, 12 divisors, 19 antidivisors and 1150704 totatives.
2307484 has a triangular digit sum 28 in base 10.
2307484 = 5768722 - 5768702 = 15202 - 542 is the difference of 2 nonnegative squares in 2 ways.
2307484 is the difference of 2 positive pentagonal numbers in 3 ways.
2307484 is not the sum of 3 positive squares.
23074842 = 3399842 + 22823002 is the sum of 2 positive squares in 1 way.
23074842 is the sum of 3 positive squares.
2307484 is a proper divisor of 379732 - 1.

Wednesday, June 5, 2019

Number of the day: 909307

Properties of the number 909307:

909307 is a cyclic number.
909307 = 7 × 129901 is semiprime and squarefree.
909307 has 2 distinct prime factors, 4 divisors, 19 antidivisors and 779400 totatives.
909307 has a triangular digit sum 28 in base 10.
Reversing the decimal digits of 909307 results in an emirpimes.
909307 = 193 + 533 + 913 is the sum of 3 positive cubes in 1 way.
909307 = 4546542 - 4546532 = 649542 - 649472 is the difference of 2 nonnegative squares in 2 ways.
909307 is the difference of 2 positive pentagonal numbers in 2 ways.
909307 = 1532 + 1632 + 9272 is the sum of 3 positive squares.
9093072 = 4397402 + 7959072 is the sum of 2 positive squares in 1 way.
9093072 is the sum of 3 positive squares.
909307 is a proper divisor of 113433 - 1.
909307 is an emirpimes in (at least) the following bases: 2, 10, 14, 16, 17, 21, 23, 25, 28, 30, 34, 37, 38, 40, 51, 53, 54, 56, 59, 61, 73, 78, 79, 81, 84, 85, 86, 87, 93, and 95.

Monday, June 3, 2019

Number of the day: 462130872

Properties of the number 462130872:

462130872 = 23 × 3 × 7 × 2750779 is the 437669513th composite number and is not squarefree.
462130872 has 4 distinct prime factors, 32 divisors, 69 antidivisors and 132037344 totatives.
462130872 has a semiprime digit sum 33 in base 10.
462130872 = 1155327192 - 1155327172 = 577663612 - 577663572 = 385109092 - 385109032 = 192554592 - 192554472 = 165046812 - 165046672 = 82523512 - 82523232 = 55015792 - 55015372 = 27508212 - 27507372 is the difference of 2 nonnegative squares in 8 ways.
462130872 = 2422 + 7722 + 214822 is the sum of 3 positive squares.
4621308722 is the sum of 3 positive squares.
462130872 is a proper divisor of 71305642 - 1.
462130872 = '46213087' + '2' is the concatenation of 2 prime numbers.

Sunday, June 2, 2019

Number of the day: 9331

Properties of the number 9331:

9331 = 7 × 31 × 43 is a sphenic number and squarefree.
9331 has 3 distinct prime factors, 8 divisors, 9 antidivisors and 7560 totatives.
Reversing the decimal digits of 9331 results in a semiprime.
9331 = 192 + … + 322 is the sum of at least 2 consecutive positive squares in 1 way.
9331 = 203 + 113 is the sum of 2 positive cubes in 1 way.
9331 = 46662 - 46652 = 6702 - 6632 = 1662 - 1352 = 1302 - 872 is the difference of 2 nonnegative squares in 4 ways.
9331 is the sum of 2 positive triangular numbers.
9331 is the difference of 2 positive pentagonal numbers in 4 ways.
9331 = 92 + 412 + 872 is the sum of 3 positive squares.
93312 is the sum of 3 positive squares.
9331 is a proper divisor of 376 - 1.
9331 is palindromic in (at least) the following bases: 6, 36, 53, -6, and -37.
9331 in base 6 = 111111 and consists of only the digit '1'.
9331 in base 35 = 7ll and consists of only the digits '7' and 'l'.
9331 in base 36 = 777 and consists of only the digit '7'.
9331 in base 52 = 3NN and consists of only the digits '3' and 'N'.
9331 in base 53 = 3H3 and consists of only the digits '3' and 'H'.

The number 9331 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A003464: a(n) = (6^n - 1)/5.
A005937: Pseudoprimes to base 6.
A022170: Triangle of Gaussian binomial coefficients [ n,k ] for q = 6.
A023037: a(n) = n^0+n^1+...+n^(n-1), or a(n) = (n^n-1)/(n-1) with a(0)=0; a(1)=1.
A025012: Central heptanomial coefficients: largest coefficient of (1+x+...+x^6)^n.
A053700: a(n) = 111111 in base n.
A057075: Table read by antidiagonals of T(n,k)=floor[n^n/k] with n,k >= 1.
A125118: Triangle read by rows: T(n,k) = value of the n-th repunit in base (k+1) representation, 1<=k<=n.
A201552: Square array read by diagonals: T(n,k) = number of arrays of n integers in -k..k with sum equal to 0.
A262508: Numbers that occur only once in A155043; positions of zeros in A262505, ones in A262507.

Saturday, June 1, 2019

Number of the day: 3816

Properties of the number 3816:

3816 = 23 × 32 × 53 is the 3286th composite number and is not squarefree.
3816 has 3 distinct prime factors, 24 divisors, 9 antidivisors and 1248 totatives.
3816 has a Fibonacci digit product 144 in base 10.
3816 = 73 + 93 + 143 is the sum of 3 positive cubes in 1 way.
3816 = 9552 - 9532 = 4792 - 4752 = 3212 - 3152 = 1652 - 1532 = 1152 - 972 = 712 - 352 is the difference of 2 nonnegative squares in 6 ways.
3816 is the difference of 2 positive pentagonal numbers in 1 way.
3816 = 302 + 542 is the sum of 2 positive squares in 1 way.
3816 = 142 + 162 + 582 is the sum of 3 positive squares.
38162 = 20162 + 32402 is the sum of 2 positive squares in 1 way.
38162 is the sum of 3 positive squares.
3816 is a proper divisor of 1072 - 1.
3816 = '381' + '6' is the concatenation of 2 semiprime numbers.
3816 is palindromic in (at least) the following bases: 31, 71, and -41.
3816 in base 16 = ee8 and consists of only the digits '8' and 'e'.
3816 in base 19 = aag and consists of only the digits 'a' and 'g'.
3816 in base 31 = 3u3 and consists of only the digits '3' and 'u'.
3816 in base 43 = 22W and consists of only the digits '2' and 'W'.
3816 in base 61 = 11Y and consists of only the digits '1' and 'Y'.

The number 3816 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A000567: Octagonal numbers: n*(3*n-2). Also called star numbers.
A014642: Even octagonal numbers: 4*n*(3*n-1).
A118807: Number of partitions of n having no parts with multiplicity 3.
A135190: Numbers n that raised to the powers from 1 to k (with k>=1) are multiple of the sum of their digits (n raised to k+1 must not be a multiple). Case k=5.
A138990: a(n) = Frobenius number for 4 successive primes = F[p(n),p(n+1),p(n+2),p(n+3)].
A139229: First differences of perfect numbers A000396, divided by 2.
A173682: Number of ways of writing n as a sum of 9 nonnegative cubes.
A219047: Numbers n such that 3^n - 28 is prime.
A257211: Numbers n such that the decimal expansions of both n and n^2 have 1 as smallest digit and 8 as largest digit.
A269656: T(n,k)=Number of length-n 0..k arrays with no adjacent pair x,x+1 repeated.