644634532 has 12 divisors (see below), whose sum is σ = 1129355136. Its totient is φ = 321961640.

The previous prime is 644634517. The next prime is 644634541. The reversal of 644634532 is 235436446.

It is a happy number.

644634532 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 644634491 and 644634500.

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, 84808 + ... + 92095.

It is an arithmetic number, because the mean of its divisors is an integer number (94112928).

Almost surely, 2^644634532 is an apocalyptic number.

It is an amenable number.

644634532 is a deficient number, since it is larger than the sum of its proper divisors (484720604).

644634532 is a wasteful number, since it uses less digits than its factorization.

644634532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177818 (or 177816 counting only the distinct ones).

The product of its digits is 207360, while the sum is 37.

The square root of 644634532 is about 25389.6540346654. The cubic root of 644634532 is about 863.8490409126.

The spelling of 644634532 in words is "six hundred forty-four million, six hundred thirty-four thousand, five hundred thirty-two".