644446315 has 12 divisors (see below), whose sum is σ = 808424064. Its totient is φ = 493139504.

The previous prime is 644446303. The next prime is 644446333. The reversal of 644446315 is 513644446.

It is not a de Polignac number, because 644446315 - 2¹¹ = 644444267 is a prime.

It is a super-2 number, since 2×644446315² = 830622105834158450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 119179 + ... + 124468.

It is an arithmetic number, because the mean of its divisors is an integer number (67368672).

Almost surely, 2^644446315 is an apocalyptic number.

644446315 is a deficient number, since it is larger than the sum of its proper divisors (163977749).

644446315 is a wasteful number, since it uses less digits than its factorization.

644446315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243698 (or 243675 counting only the distinct ones).

The product of its digits is 138240, while the sum is 37.

The square root of 644446315 is about 25385.9471952496. The cubic root of 644446315 is about 863.7649586957.

The spelling of 644446315 in words is "six hundred forty-four million, four hundred forty-six thousand, three hundred fifteen".