644714750056764 has 12 divisors (see below), whose sum is σ = 1504334416799144. Its totient is φ = 214904916685584.

The previous prime is 644714750056753. The next prime is 644714750056781. The reversal of 644714750056764 is 467650057417446.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×644714750056764² (a number of 30 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 644714750056695 and 644714750056704.

It is a congruent number.

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, 26863114585687 + ... + 26863114585710.

Almost surely, 2^{644714750056764} is an apocalyptic number.

It is an amenable number.

644714750056764 is an abundant number, since it is smaller than the sum of its proper divisors (859619666742380).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644714750056764 is a wasteful number, since it uses less digits than its factorization.

644714750056764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53726229171404 (or 53726229171402 counting only the distinct ones).

The product of its (nonzero) digits is 474163200, while the sum is 66.

The spelling of 644714750056764 in words is "six hundred forty-four trillion, seven hundred fourteen billion, seven hundred fifty million, fifty-six thousand, seven hundred sixty-four".