644612252 has 12 divisors (see below), whose sum is σ = 1131421200. Its totient is φ = 321349056.

The previous prime is 644612251. The next prime is 644612323. The reversal of 644612252 is 252216446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644612251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 237752 + ... + 240447.

It is an arithmetic number, because the mean of its divisors is an integer number (94285100).

Almost surely, 2^644612252 is an apocalyptic number.

It is an amenable number.

644612252 is a deficient number, since it is larger than the sum of its proper divisors (486808948).

644612252 is a wasteful number, since it uses less digits than its factorization.

644612252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 478540 (or 478538 counting only the distinct ones).

The product of its digits is 23040, while the sum is 32.

The square root of 644612252 is about 25389.2152694801. The cubic root of 644612252 is about 863.8390886180.

Adding to 644612252 its reverse (252216446), we get a palindrome (896828698).

The spelling of 644612252 in words is "six hundred forty-four million, six hundred twelve thousand, two hundred fifty-two".