644374942252 has 24 divisors (see below), whose sum is σ = 1144166833152. Its totient is φ = 317475118800.

The previous prime is 644374942249. The next prime is 644374942271. The reversal of 644374942252 is 252249473446.

It is a self number, because there is not a number n which added to its sum of digits gives 644374942252.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 104574 + ... + 1140037.

It is an arithmetic number, because the mean of its divisors is an integer number (47673618048).

Almost surely, 2^644374942252 is an apocalyptic number.

It is an amenable number.

644374942252 is a deficient number, since it is larger than the sum of its proper divisors (499791890900).

644374942252 is a wasteful number, since it uses less digits than its factorization.

644374942252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1246509 (or 1246507 counting only the distinct ones).

The product of its digits is 11612160, while the sum is 52.

The spelling of 644374942252 in words is "six hundred forty-four billion, three hundred seventy-four million, nine hundred forty-two thousand, two hundred fifty-two".