644337952 has 24 divisors (see below), whose sum is σ = 1269181116. Its totient is φ = 322006272.

The previous prime is 644337917. The next prime is 644337959. The reversal of 644337952 is 259733446.

It can be written as a sum of positive squares in 2 ways, for example, as 606932496 + 37405456 = 24636^2 + 6116^2 .

It is a junction number, because it is equal to n+sod(n) for n = 644337899 and 644337908.

It is not an unprimeable number, because it can be changed into a prime (644337959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82438 + ... + 89914.

Almost surely, 2^644337952 is an apocalyptic number.

It is an amenable number.

644337952 is a deficient number, since it is larger than the sum of its proper divisors (624843164).

644337952 is a wasteful number, since it uses less digits than its factorization.

644337952 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10180 (or 10172 counting only the distinct ones).

The product of its digits is 544320, while the sum is 43.

The square root of 644337952 is about 25383.8127947714. The cubic root of 644337952 is about 863.7165422454.

The spelling of 644337952 in words is "six hundred forty-four million, three hundred thirty-seven thousand, nine hundred fifty-two".