81597904888 has 64 divisors (see below), whose sum is σ = 158122800000. Its totient is φ = 39461520384.

The previous prime is 81597904873. The next prime is 81597904909. The reversal of 81597904888 is 88840979518.

It is a super-2 number, since 2×81597904888² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

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, 6124378 + ... + 6137686.

It is an arithmetic number, because the mean of its divisors is an integer number (2470668750).

Almost surely, 2^81597904888 is an apocalyptic number.

It is an amenable number.

81597904888 is a deficient number, since it is larger than the sum of its proper divisors (76524895112).

81597904888 is a wasteful number, since it uses less digits than its factorization.

81597904888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13592 (or 13588 counting only the distinct ones).

The product of its (nonzero) digits is 46448640, while the sum is 67.

The spelling of 81597904888 in words is "eighty-one billion, five hundred ninety-seven million, nine hundred four thousand, eight hundred eighty-eight".