Sunday, November 13, 2016

Number of the day: 8777

Properties of the number 8777:

8777 = 67 × 131 is semiprime and squarefree.
8777 has 2 distinct prime factors, 4 divisors, 7 antidivisors and 8580 totatives.
8777 has a prime digit sum 29 in base 10.
Reversing the decimal digits of 8777 results in an emirpimes.
8777 = 43892 - 43882 = 992 - 322 is the difference of 2 nonnegative squares in 2 ways.
8777 is the difference of 2 positive pentagonal numbers in 1 way.
8777 = 122 + 132 + 922 is the sum of 3 positive squares.
87772 is the sum of 3 positive squares.
8777 is a divisor of 15716 - 1.
8777 = '877' + '7' is the concatenation of 2 prime numbers.
8777 = '87' + '77' is the concatenation of 2 semiprime numbers.
8777 is an emirpimes in (at least) the following bases: 3, 4, 6, 8, 10, 11, 12, 15, 17, 18, 19, 21, 22, 23, 27, 30, 31, 33, 34, 35, 37, 49, 50, 56, 57, 70, 71, 76, 78, 81, 82, 87, 88, 89, 90, 93, 94, 99, and 100.
8777 is palindromic in (at least) the following bases: 65, -9, -21, -32, -43, and -75.
8777 in base 8 = 21111 and consists of only the digits '1' and '2'.
8777 consists of only the digits '7' and '8'.
8777 in base 31 = 944 and consists of only the digits '4' and '9'.

The number 8777 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A033566: a(n) = (2*n+1) * (4*n-1).
A042753: Denominators of continued fraction convergents to sqrt(907).
A089372: Number of Motzkin paths of length n with no peaks at level 1.
A151793: Partial sums of A151782.
A153257: a(n)=n^3-(n+1)^2.
A178977: (3*n+2)*(3*n+5)/2.
A182988: The number of dominance pairs of integer partitions of n according to either/or dominance order, where dominance between two partitions x and y means that x is majorized by y or y is majorized by x.
A201362: Numbers n such that (2^n - n - 1)*2^n + 1 is prime.
A256340: Numbers which have only digits 7 and 8 in base 10.
A258349: Expansion of Product_{k>=1} 1/(1-x^k)^(k*(k-1)/2).

No comments:

Post a Comment