81599958188 has 12 divisors (see below), whose sum is σ = 163199916432. Its totient is φ = 34971410640.

The previous prime is 81599958161. The next prime is 81599958191. The reversal of 81599958188 is 88185999518.

81599958188 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1457142083 + ... + 1457142138.

It is an arithmetic number, because the mean of its divisors is an integer number (13599993036).

Almost surely, 2^81599958188 is an apocalyptic number.

It is an amenable number.

81599958188 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

81599958188 is a wasteful number, since it uses less digits than its factorization.

81599958188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2914284232 (or 2914284230 counting only the distinct ones).

The product of its digits is 74649600, while the sum is 71.

The spelling of 81599958188 in words is "eighty-one billion, five hundred ninety-nine million, nine hundred fifty-eight thousand, one hundred eighty-eight".