644339316 has 24 divisors (see below), whose sum is σ = 1505024640. Its totient is φ = 214556032.

The previous prime is 644339299. The next prime is 644339323. The reversal of 644339316 is 613933446.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15756 + ... + 39203.

It is an arithmetic number, because the mean of its divisors is an integer number (62709360).

Almost surely, 2^644339316 is an apocalyptic number.

It is an amenable number.

644339316 is an abundant number, since it is smaller than the sum of its proper divisors (860685324).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644339316 is a wasteful number, since it uses less digits than its factorization.

644339316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55943 (or 55941 counting only the distinct ones).

The product of its digits is 139968, while the sum is 39.

The square root of 644339316 is about 25383.8396622733. The cubic root of 644339316 is about 863.7171517126.

The spelling of 644339316 in words is "six hundred forty-four million, three hundred thirty-nine thousand, three hundred sixteen".