644375332 has 12 divisors (see below), whose sum is σ = 1128749440. Its totient is φ = 321875496.

The previous prime is 644375317. The next prime is 644375351. The reversal of 644375332 is 233573446.

It is a super-2 number, since 2×644375332² = 830439136980220448, which contains 22 as substring.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 644375291 and 644375300.

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, 73368 + ... + 81679.

Almost surely, 2^644375332 is an apocalyptic number.

It is an amenable number.

644375332 is a deficient number, since it is larger than the sum of its proper divisors (484374108).

644375332 is a wasteful number, since it uses less digits than its factorization.

644375332 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156090 (or 156088 counting only the distinct ones).

The product of its digits is 181440, while the sum is 37.

The square root of 644375332 is about 25384.5490800999. The cubic root of 644375332 is about 863.7332441950.

The spelling of 644375332 in words is "six hundred forty-four million, three hundred seventy-five thousand, three hundred thirty-two".