Saturday, September 30, 2017

Number of the day: 955738977518

Properties of the number 955738977518:

955738977518 = 2 × 132 × 17 × 2671 × 62273 is composite and not squarefree.
955738977518 has 5 distinct prime factors, 48 divisors, 55 antidivisors and 415000535040 totatives.
955738977518 has a semiprime digit sum 74 in base 10.
Reversing the decimal digits of 955738977518 results in a semiprime.
955738977518 is the difference of 2 positive pentagonal numbers in 11 ways.
955738977518 = 3872 + 27822 + 9776152 is the sum of 3 positive squares.
9557389775182 = 4497595188322 + 8432990978102 = 1427856288822 + 9450128344802 = 4078841364002 + 8643306800182 = 4952685937682 + 8174019899502 = 908168259182 + 9514143667602 = 6409651906322 + 7089433105302 = 6054455061202 + 7395084396182 = 440735566702 + 9547222186322 = 2316643558322 + 9272370890902 = 3189896719182 + 9009342830402 = 2820976863682 + 9131581946702 = 5640369931202 + 7715563903822 = 3265175702402 + 8982334159182 = 2744464519502 + 9154868312322 = 5704736704182 + 7668094838402 = 3675919144302 + 8822205946322 = 2319371397202 + 9271688931182 = 4881694764182 + 8216614603602 = 5706992417102 + 7666416168322 = 6729759664182 + 6786312266402 = 1345943396322 + 9462142235702 = 1425075991502 + 9450548012322 is the sum of 2 positive squares in 22 ways.
9557389775182 is the sum of 3 positive squares.
955738977518 is a proper divisor of 257194376 - 1.
955738977518 = '955' + '738977518' is the concatenation of 2 semiprime numbers.

Friday, September 29, 2017

Number of the day: 976985

Properties of the number 976985:

976985 = 5 × 37 × 5281 is a sphenic number and squarefree.
976985 has 3 distinct prime factors, 8 divisors, 11 antidivisors and 760320 totatives.
Reversing the decimal digits of 976985 results in a semiprime.
976985 = 4884932 - 4884922 = 977012 - 976962 = 132212 - 131842 = 27332 - 25482 is the difference of 2 nonnegative squares in 4 ways.
976985 is the difference of 2 positive pentagonal numbers in 4 ways.
976985 = 6162 + 7732 = 3322 + 9312 = 2932 + 9442 = 292 + 9882 is the sum of 2 positive squares in 4 ways.
976985 = 422 + 552 + 9862 is the sum of 3 positive squares.
9769852 = 6310252 + 7458602 = 3550152 + 9102002 = 406252 + 9761402 = 5531842 + 8052872 = 2621082 + 9411692 = 573042 + 9753032 = 6181842 + 7565372 = 5151512 + 8301322 = 2180732 + 9523362 = 5861912 + 7815882 = 5492242 + 8079932 = 3010172 + 9294562 = 3168602 + 9241752 is the sum of 2 positive squares in 13 ways.
9769852 is the sum of 3 positive squares.
976985 is a proper divisor of 115312 - 1.

Thursday, September 28, 2017

Number of the day: 829888

Properties of the number 829888:

829888 = 26 × 12967 is the 763731th composite number and is not squarefree.
829888 has 2 distinct prime factors, 14 divisors, 25 antidivisors and 414912 totatives.
829888 has a prime digit sum 43 in base 10.
829888 = 2074732 - 2074712 = 1037382 - 1037342 = 518722 - 518642 = 259422 - 259262 = 129832 - 129512 is the difference of 2 nonnegative squares in 5 ways.
829888 is the sum of 2 positive triangular numbers.
829888 is the difference of 2 positive pentagonal numbers in 1 way.
829888 is not the sum of 3 positive squares.
8298882 is the sum of 3 positive squares.
829888 is a proper divisor of 1932161 - 1.

Wednesday, September 27, 2017

Number of the day: 58200

Properties of the number 58200:

58200 = 23 × 3 × 52 × 97 is the 52305th composite number and is not squarefree.
58200 has 4 distinct prime factors, 48 divisors, 19 antidivisors and 15360 totatives.
58200 has an emirpimes digit sum 15 in base 10.
58200 has a triangular digit sum 15 in base 10.
58200 is the difference of 2 nonnegative squares in 12 ways.
58200 is the sum of 2 positive triangular numbers.
58200 is the difference of 2 positive pentagonal numbers in 1 way.
58200 = 202 + 342 + 2382 is the sum of 3 positive squares.
582002 = 390002 + 432002 = 52802 + 579602 = 111602 + 571202 = 305522 + 495362 = 253442 + 523922 = 349202 + 465602 = 162962 + 558722 is the sum of 2 positive squares in 7 ways.
582002 is the sum of 3 positive squares.
58200 is a proper divisor of 1934 - 1.
58200 in base 5 = 3330300 and consists of only the digits '0' and '3'.
58200 in base 22 = 5a5a and consists of only the digits '5' and 'a'.
58200 in base 58 = HHQ and consists of only the digits 'H' and 'Q'.

The number 58200 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A015578: Expansion of x/(1-8x-11x^2).
A018211: Alkane (or paraffin) numbers l(10,n).

Tuesday, September 26, 2017

Number of the day: 5370

Properties of the number 5370:

5370 = 2 × 3 × 5 × 179 is the 4661th composite number and is squarefree.
5370 has 4 distinct prime factors, 16 divisors, 9 antidivisors and 1424 totatives.
5370 has an emirpimes digit sum 15 in base 10.
5370 has a triangular digit sum 15 in base 10.
5370 is the sum of 2 positive triangular numbers.
5370 is the difference of 2 positive pentagonal numbers in 1 way.
5370 is the difference of 2 positive pentagonal pyramidal numbers in 2 ways.
5370 = (60 × (3 × 60-1))/2 is a pentagonal number.
5370 = 42 + 52 + 732 is the sum of 3 positive squares.
53702 = 32222 + 42962 is the sum of 2 positive squares in 1 way.
53702 is the sum of 3 positive squares.
5370 is a proper divisor of 3592 - 1.
5370 is palindromic in (at least) the following bases: 44, 59, -23, -61, and -91.
5370 in base 22 = b22 and consists of only the digits '2' and 'b'.
5370 in base 43 = 2cc and consists of only the digits '2' and 'c'.
5370 in base 44 = 2Y2 and consists of only the digits '2' and 'Y'.
5370 in base 58 = 1YY and consists of only the digits '1' and 'Y'.
5370 in base 59 = 1W1 and consists of only the digits '1' and 'W'.

The number 5370 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A002625: Expansion of 1/((1-x)^3*(1-x^2)^2*(1-x^3)).
A014633: Even pentagonal numbers.
A049452: Pentagonal numbers with even index.
A196485: T(n,k)=Number of nXk 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 3,0,2,1,4 for x=0,1,2,3,4
A222604: Number of nX1 0..3 arrays with exactly floor(nX1/2) elements equal to at least one king-move neighbor, with new values introduced in row major 0..3 order
A222747: T(n,k)=Number of nXk 0..3 arrays with exactly floor(nXk/2) elements equal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..3 order
A226253: Number of ways of writing n as the sum of 9 triangular numbers.
A232696: E.g.f. A(x) satisfies: A'(x) = A(x/A'(x)) with A(0)=1.
A246479: T(n,k)=Number of length n+3 0..k arrays with no pair in any consecutive four terms totalling exactly k
A263373: T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with each row and column divisible by 7, read as a base-3 number with top and left being the most significant digits.

Monday, September 25, 2017

Number of the day: 672028146

Properties of the number 672028146:

672028146 = 2 × 32 × 37334897 is the 637149995th composite number and is not squarefree.
672028146 has 3 distinct prime factors, 12 divisors, 7 antidivisors and 224009376 totatives.
672028146 has a triangular digit sum 36 in base 10.
672028146 is the sum of 2 positive triangular numbers.
672028146 is the difference of 2 positive pentagonal numbers in 2 ways.
672028146 = 48752 + 254612 is the sum of 2 positive squares in 1 way.
672028146 = 9292 + 13242 + 258732 is the sum of 3 positive squares.
6720281462 = 2482447502 + 6244968962 is the sum of 2 positive squares in 1 way.
6720281462 is the sum of 3 positive squares.
672028146 is a proper divisor of 1789264162 - 1.
672028146 = '67202' + '8146' is the concatenation of 2 semiprime numbers.

Sunday, September 24, 2017

Number of the day: 3930

Gerolamo Cardano was born on this day 516 years ago.

Properties of the number 3930:

3930 = 2 × 3 × 5 × 131 is the 3384th composite number and is squarefree.
3930 has 4 distinct prime factors, 16 divisors, 11 antidivisors and 1040 totatives.
3930 has an emirpimes digit sum 15 in base 10.
3930 has a triangular digit sum 15 in base 10.
3930 = 262 + … + 302 is the sum of at least 2 consecutive positive squares in 1 way.
3930 is the difference of 2 positive pentagonal numbers in 1 way.
3930 = 72 + 202 + 592 is the sum of 3 positive squares.
39302 = 23582 + 31442 is the sum of 2 positive squares in 1 way.
39302 is the sum of 3 positive squares.
3930 is a proper divisor of 10492 - 1.
3930 is palindromic in (at least) the following bases: 33, and -20.
3930 in base 19 = agg and consists of only the digits 'a' and 'g'.
3930 in base 32 = 3qq and consists of only the digits '3' and 'q'.
3930 in base 33 = 3k3 and consists of only the digits '3' and 'k'.
3930 in base 62 = 11O and consists of only the digits '1' and 'O'.

The number 3930 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A027578: Sums of five consecutive squares: a(n) = n^2 + (n+1)^2 + (n+2)^2 + (n+3)^2 + (n+4)^2.
A075386: Sum of terms of n-th group in A075383.
A076409: Sum of the quadratic residues of prime(n).
A113744: Generalized Mancala solitaire (A002491); to get n-th term, start with n and successively round up to next 7 multiples of n-1, n-2, ..., 1, for n>=1.
A138989: a(n) = Frobenius number for 3 successive primes = F[p(n),p(n+1),p(n+2)].
A211978: Total number of parts in all partitions of n plus the sum of largest parts of all partitions of n.
A251829: T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row and column sum not 3 or 6 and every diagonal and antidiagonal sum 3 or 6
A256874: Numbers divisible by prime(d) for each digit d in their base 4 representation, none of which may be zero.
A282035: Sum of quadratic residues of (n-th prime == 3 mod 4).
A284949: Triangle read by rows: T(n,k) = number of reversible string structures of length n using exactly k different symbols.