81568831533984 has 96 divisors (see below), whose sum is σ = 244339067528640. Its totient is φ = 26454756162816.

The previous prime is 81568831533971. The next prime is 81568831534009. The reversal of 81568831533984 is 48933513886518.

81568831533984 is a `hidden beast` number, since 8 + 1 + 5 + 6 + 8 + 8 + 3 + 1 + 533 + 9 + 84 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1275756814 + ... + 1275820749.

It is an arithmetic number, because the mean of its divisors is an integer number (2545198620090).

Almost surely, 2^{81568831533984} is an apocalyptic number.

It is an amenable number.

81568831533984 is an abundant number, since it is smaller than the sum of its proper divisors (162770235994656).

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

81568831533984 is a wasteful number, since it uses less digits than its factorization.

81568831533984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2551577619 (or 2551577605 counting only the distinct ones).

The product of its digits is 597196800, while the sum is 72.

The spelling of 81568831533984 in words is "eighty-one trillion, five hundred sixty-eight billion, eight hundred thirty-one million, five hundred thirty-three thousand, nine hundred eighty-four".