644594716 has 12 divisors (see below), whose sum is σ = 1166938920. Its totient is φ = 311183600.

The previous prime is 644594701. The next prime is 644594759. The reversal of 644594716 is 617495446.

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, 2778310 + ... + 2778541.

It is an arithmetic number, because the mean of its divisors is an integer number (97244910).

Almost surely, 2^644594716 is an apocalyptic number.

It is an amenable number.

644594716 is a deficient number, since it is larger than the sum of its proper divisors (522344204).

644594716 is a wasteful number, since it uses less digits than its factorization.

644594716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5556884 (or 5556882 counting only the distinct ones).

The product of its digits is 725760, while the sum is 46.

The square root of 644594716 is about 25388.8699236496. The cubic root of 644594716 is about 863.8312552682.

The spelling of 644594716 in words is "six hundred forty-four million, five hundred ninety-four thousand, seven hundred sixteen".