644883912 has 48 divisors (see below), whose sum is σ = 1771174080. Its totient is φ = 211932000.

The previous prime is 644883907. The next prime is 644883929. The reversal of 644883912 is 219388446.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 57964 + ... + 68187.

It is an arithmetic number, because the mean of its divisors is an integer number (36899460).

Almost surely, 2^644883912 is an apocalyptic number.

It is an amenable number.

644883912 is an abundant number, since it is smaller than the sum of its proper divisors (1126290168).

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

644883912 is a wasteful number, since it uses less digits than its factorization.

644883912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126234 (or 126227 counting only the distinct ones).

The product of its digits is 331776, while the sum is 45.

The square root of 644883912 is about 25394.5646152873. The cubic root of 644883912 is about 863.9604212837.

The spelling of 644883912 in words is "six hundred forty-four million, eight hundred eighty-three thousand, nine hundred twelve".