816231664 has 10 divisors (see below), whose sum is σ = 1581448880. Its totient is φ = 408115824.

The previous prime is 816231589. The next prime is 816231671. The reversal of 816231664 is 466132618.

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 as a sum of consecutive naturals, namely, 25507224 + ... + 25507255.

It is an arithmetic number, because the mean of its divisors is an integer number (158144888).

Almost surely, 2^816231664 is an apocalyptic number.

It is an amenable number.

816231664 is a deficient number, since it is larger than the sum of its proper divisors (765217216).

816231664 is a wasteful number, since it uses less digits than its factorization.

816231664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51014487 (or 51014481 counting only the distinct ones).

The product of its digits is 41472, while the sum is 37.

The square root of 816231664 is about 28569.7683574789. The cubic root of 816231664 is about 934.5541695228.

The spelling of 816231664 in words is "eight hundred sixteen million, two hundred thirty-one thousand, six hundred sixty-four".