816380664 has 64 divisors (see below), whose sum is σ = 2357475840. Its totient is φ = 232834560.

The previous prime is 816380659. The next prime is 816380683. The reversal of 816380664 is 466083618.

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, 86464 + ... + 95439.

It is an arithmetic number, because the mean of its divisors is an integer number (36835560).

Almost surely, 2^816380664 is an apocalyptic number.

It is an amenable number.

816380664 is an abundant number, since it is smaller than the sum of its proper divisors (1541095176).

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

816380664 is a wasteful number, since it uses less digits than its factorization.

816380664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181940 (or 181936 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 42.

The square root of 816380664 is about 28572.3758900096. The cubic root of 816380664 is about 934.6110325047.

The spelling of 816380664 in words is "eight hundred sixteen million, three hundred eighty thousand, six hundred sixty-four".