644404504 has 16 divisors (see below), whose sum is σ = 1219552200. Its totient is φ = 319190592.

The previous prime is 644404487. The next prime is 644404511. The reversal of 644404504 is 405404446.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 375549 + ... + 377260.

Almost surely, 2^644404504 is an apocalyptic number.

It is an amenable number.

644404504 is a deficient number, since it is larger than the sum of its proper divisors (575147696).

644404504 is a wasteful number, since it uses less digits than its factorization.

644404504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 752922 (or 752918 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 31.

The square root of 644404504 is about 25385.1236750976. The cubic root of 644404504 is about 863.7462782373.

The spelling of 644404504 in words is "six hundred forty-four million, four hundred four thousand, five hundred four".