81590668 has 12 divisors (see below), whose sum is σ = 143142552. Its totient is φ = 40692800.

The previous prime is 81590653. The next prime is 81590671. The reversal of 81590668 is 86609518.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23830 + ... + 27037.

It is an arithmetic number, because the mean of its divisors is an integer number (11928546).

Almost surely, 2^81590668 is an apocalyptic number.

It is an amenable number.

81590668 is a deficient number, since it is larger than the sum of its proper divisors (61551884).

81590668 is a wasteful number, since it uses less digits than its factorization.

81590668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51272 (or 51270 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 43.

The square root of 81590668 is about 9032.7552828580. The cubic root of 81590668 is about 433.7240418320.

The spelling of 81590668 in words is "eighty-one million, five hundred ninety thousand, six hundred sixty-eight".