81590790 has 32 divisors (see below), whose sum is σ = 196162560. Its totient is φ = 21719264.

The previous prime is 81590777. The next prime is 81590827. The reversal of 81590790 is 9709518.

It is a happy number.

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, 17707 + ... + 21833.

It is an arithmetic number, because the mean of its divisors is an integer number (6130080).

Almost surely, 2^81590790 is an apocalyptic number.

81590790 is an abundant number, since it is smaller than the sum of its proper divisors (114571770).

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

81590790 is a wasteful number, since it uses less digits than its factorization.

81590790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4796.

The product of its (nonzero) digits is 22680, while the sum is 39.

The square root of 81590790 is about 9032.7620360552. The cubic root of 81590790 is about 433.7242580099.

The spelling of 81590790 in words is "eighty-one million, five hundred ninety thousand, seven hundred ninety".