644683272 has 32 divisors (see below), whose sum is σ = 1614821280. Its totient is φ = 214479360.

The previous prime is 644683271. The next prime is 644683297. The reversal of 644683272 is 272386446.

It is not an unprimeable number, because it can be changed into a prime (644683271) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13129 + ... + 38232.

It is an arithmetic number, because the mean of its divisors is an integer number (50463165).

Almost surely, 2^644683272 is an apocalyptic number.

It is an amenable number.

644683272 is an abundant number, since it is smaller than the sum of its proper divisors (970138008).

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

644683272 is a wasteful number, since it uses less digits than its factorization.

644683272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51893 (or 51889 counting only the distinct ones).

The product of its digits is 387072, while the sum is 42.

The square root of 644683272 is about 25390.6138563052. The cubic root of 644683272 is about 863.8708118743.

The spelling of 644683272 in words is "six hundred forty-four million, six hundred eighty-three thousand, two hundred seventy-two".