644102052634256 has 20 divisors (see below), whose sum is σ = 1255420467864192. Its totient is φ = 320122577056416.

The previous prime is 644102052634181. The next prime is 644102052634267. The reversal of 644102052634256 is 652436250201446.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120528076040 + ... + 120528081383.

Almost surely, 2^{644102052634256} is an apocalyptic number.

It is an amenable number.

644102052634256 is a deficient number, since it is larger than the sum of its proper divisors (611318415229936).

644102052634256 is a wasteful number, since it uses less digits than its factorization.

644102052634256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241056157598 (or 241056157592 counting only the distinct ones).

The product of its (nonzero) digits is 8294400, while the sum is 50.

The spelling of 644102052634256 in words is "six hundred forty-four trillion, one hundred two billion, fifty-two million, six hundred thirty-four thousand, two hundred fifty-six".