81856027164 has 48 divisors (see below), whose sum is σ = 202160766080. Its totient is φ = 25706445120.

The previous prime is 81856027163. The next prime is 81856027171. The reversal of 81856027164 is 46172065818.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81856027163) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 950494 + ... + 1033029.

Almost surely, 2^81856027164 is an apocalyptic number.

It is an amenable number.

81856027164 is an abundant number, since it is smaller than the sum of its proper divisors (120304738916).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81856027164 is a wasteful number, since it uses less digits than its factorization.

81856027164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1983730 (or 1983728 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 48.

The spelling of 81856027164 in words is "eighty-one billion, eight hundred fifty-six million, twenty-seven thousand, one hundred sixty-four".