664634564 has 24 divisors (see below), whose sum is σ = 1269571968. Its totient is φ = 301934240.

The previous prime is 664634527. The next prime is 664634603. The reversal of 664634564 is 465436466.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (44).

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, 104582 + ... + 110754.

It is an arithmetic number, because the mean of its divisors is an integer number (52898832).

Almost surely, 2^664634564 is an apocalyptic number.

It is an amenable number.

664634564 is a deficient number, since it is larger than the sum of its proper divisors (604937404).

664634564 is a wasteful number, since it uses less digits than its factorization.

664634564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8635 (or 8633 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 44.

The square root of 664634564 is about 25780.5074426397. The cubic root of 664634564 is about 872.6919587602.

The spelling of 664634564 in words is "six hundred sixty-four million, six hundred thirty-four thousand, five hundred sixty-four".