81715051 has 12 divisors (see below), whose sum is σ = 91299712. Its totient is φ = 73062000.

The previous prime is 81715033. The next prime is 81715057. The reversal of 81715051 is 15051718.

It is not a de Polignac number, because 81715051 - 2⁵ = 81715019 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81715057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1846 + ... + 12916.

Almost surely, 2^81715051 is an apocalyptic number.

81715051 is the 7381-st pentagonal number.

81715051 is a deficient number, since it is larger than the sum of its proper divisors (9584661).

81715051 is a wasteful number, since it uses less digits than its factorization.

81715051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11154 (or 11143 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 28.

The square root of 81715051 is about 9039.6377692914. The cubic root of 81715051 is about 433.9443305322.

Adding to 81715051 its reverse (15051718), we get a palindrome (96766769).

The spelling of 81715051 in words is "eighty-one million, seven hundred fifteen thousand, fifty-one".