644937052 has 12 divisors (see below), whose sum is σ = 1156167936. Its totient is φ = 314603360.

The previous prime is 644937049. The next prime is 644937053. The reversal of 644937052 is 250739446.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 644936996 and 644937014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644937053) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1966108 + ... + 1966435.

It is an arithmetic number, because the mean of its divisors is an integer number (96347328).

Almost surely, 2^644937052 is an apocalyptic number.

It is an amenable number.

644937052 is a deficient number, since it is larger than the sum of its proper divisors (511230884).

644937052 is a wasteful number, since it uses less digits than its factorization.

644937052 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3932588 (or 3932586 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 40.

The square root of 644937052 is about 25395.6108806227. The cubic root of 644937052 is about 863.9841514440.

The spelling of 644937052 in words is "six hundred forty-four million, nine hundred thirty-seven thousand, fifty-two".