664430644 has 12 divisors (see below), whose sum is σ = 1162987168. Its totient is φ = 332148600.

The previous prime is 664430603. The next prime is 664430659. The reversal of 664430644 is 446034466.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

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, 10729 + ... + 37999.

Almost surely, 2^664430644 is an apocalyptic number.

It is an amenable number.

664430644 is a deficient number, since it is larger than the sum of its proper divisors (498556524).

664430644 is a wasteful number, since it uses less digits than its factorization.

664430644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33366 (or 33364 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 37.

The square root of 664430644 is about 25776.5522132034. The cubic root of 664430644 is about 872.6026979056.

The spelling of 664430644 in words is "six hundred sixty-four million, four hundred thirty thousand, six hundred forty-four".