81590872 has 32 divisors (see below), whose sum is σ = 170449920. Its totient is φ = 36295840.

The previous prime is 81590863. The next prime is 81590897. The reversal of 81590872 is 27809518.

It is a congruent number.

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, 5728 + ... + 13999.

It is an arithmetic number, because the mean of its divisors is an integer number (5326560).

Almost surely, 2^81590872 is an apocalyptic number.

It is an amenable number.

81590872 is an abundant number, since it is smaller than the sum of its proper divisors (88859048).

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

81590872 is a wasteful number, since it uses less digits than its factorization.

81590872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19791 (or 19787 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 81590872 is about 9032.7665750865. The cubic root of 81590872 is about 433.7244033097.

The spelling of 81590872 in words is "eighty-one million, five hundred ninety thousand, eight hundred seventy-two".