644381596 has 24 divisors (see below), whose sum is σ = 1148775264. Its totient is φ = 316216320.

The previous prime is 644381581. The next prime is 644381611. The reversal of 644381596 is 695183446.

It is an interprime number because it is at equal distance from previous prime (644381581) and next prime (644381611).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39636 + ... + 53476.

It is an arithmetic number, because the mean of its divisors is an integer number (47865636).

Almost surely, 2^644381596 is an apocalyptic number.

It is an amenable number.

644381596 is a deficient number, since it is larger than the sum of its proper divisors (504393668).

644381596 is a wasteful number, since it uses less digits than its factorization.

644381596 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14061 (or 14059 counting only the distinct ones).

The product of its digits is 622080, while the sum is 46.

The square root of 644381596 is about 25384.6724619405. The cubic root of 644381596 is about 863.7360429818.

The spelling of 644381596 in words is "six hundred forty-four million, three hundred eighty-one thousand, five hundred ninety-six".