81557174692 has 24 divisors (see below), whose sum is σ = 166584870144. Its totient is φ = 34209391872.

The previous prime is 81557174689. The next prime is 81557174711. The reversal of 81557174692 is 29647175518.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30985453 + ... + 30988084.

It is an arithmetic number, because the mean of its divisors is an integer number (6941036256).

Almost surely, 2^81557174692 is an apocalyptic number.

It is an amenable number.

81557174692 is an abundant number, since it is smaller than the sum of its proper divisors (85027695452).

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

81557174692 is a wasteful number, since it uses less digits than its factorization.

81557174692 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61973595 (or 61973593 counting only the distinct ones).

The product of its digits is 4233600, while the sum is 55.

The spelling of 81557174692 in words is "eighty-one billion, five hundred fifty-seven million, one hundred seventy-four thousand, six hundred ninety-two".