644346272 has 12 divisors (see below), whose sum is σ = 1268556786. Its totient is φ = 322173120.

The previous prime is 644346239. The next prime is 644346277. The reversal of 644346272 is 272643446.

644346272 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 492662416 + 151683856 = 22196^2 + 12316^2 .

It is not an unprimeable number, because it can be changed into a prime (644346277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10067879 + ... + 10067942.

Almost surely, 2^644346272 is an apocalyptic number.

It is an amenable number.

644346272 is a deficient number, since it is larger than the sum of its proper divisors (624210514).

644346272 is a wasteful number, since it uses less digits than its factorization.

644346272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20135831 (or 20135823 counting only the distinct ones).

The product of its digits is 193536, while the sum is 38.

The square root of 644346272 is about 25383.9766782118. The cubic root of 644346272 is about 863.7202598031.

The spelling of 644346272 in words is "six hundred forty-four million, three hundred forty-six thousand, two hundred seventy-two".