81547956790 has 64 divisors (see below), whose sum is σ = 152652677760. Its totient is φ = 31327994880.

The previous prime is 81547956779. The next prime is 81547956803. The reversal of 81547956790 is 9765974518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 56355847 + ... + 56357293.

It is an arithmetic number, because the mean of its divisors is an integer number (2385198090).

Almost surely, 2^81547956790 is an apocalyptic number.

81547956790 is a deficient number, since it is larger than the sum of its proper divisors (71104720970).

81547956790 is a wasteful number, since it uses less digits than its factorization.

81547956790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2377.

The product of its (nonzero) digits is 19051200, while the sum is 61.

The spelling of 81547956790 in words is "eighty-one billion, five hundred forty-seven million, nine hundred fifty-six thousand, seven hundred ninety".