81568575928 has 32 divisors (see below), whose sum is σ = 174803904000. Its totient is φ = 34955141472.

The previous prime is 81568575911. The next prime is 81568575947. The reversal of 81568575928 is 82957586518.

It is a super-2 number, since 2×81568575928² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81568575928.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 737173 + ... + 840571.

It is an arithmetic number, because the mean of its divisors is an integer number (5462622000).

Almost surely, 2^81568575928 is an apocalyptic number.

It is an amenable number.

81568575928 is an abundant number, since it is smaller than the sum of its proper divisors (93235328072).

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

81568575928 is a wasteful number, since it uses less digits than its factorization.

81568575928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117499 (or 117495 counting only the distinct ones).

The product of its digits is 48384000, while the sum is 64.

The spelling of 81568575928 in words is "eighty-one billion, five hundred sixty-eight million, five hundred seventy-five thousand, nine hundred twenty-eight".