644604232 has 64 divisors (see below), whose sum is σ = 1339668720. Its totient is φ = 289456128.

The previous prime is 644604227. The next prime is 644604277. The reversal of 644604232 is 232406446.

It can be written as a sum of positive squares in 8 ways, for example, as 644448996 + 155236 = 25386^2 + 394^2 .

It is a junction number, because it is equal to n+sod(n) for n = 644604194 and 644604203.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 265488 + ... + 267904.

Almost surely, 2^644604232 is an apocalyptic number.

It is an amenable number.

644604232 is an abundant number, since it is smaller than the sum of its proper divisors (695064488).

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

644604232 is a wasteful number, since it uses less digits than its factorization.

644604232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2530 (or 2526 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 31.

The square root of 644604232 is about 25389.0573279120. The cubic root of 644604232 is about 863.8355060931.

The spelling of 644604232 in words is "six hundred forty-four million, six hundred four thousand, two hundred thirty-two".