644634124613664 has 96 divisors (see below), whose sum is σ = 1720867171968000. Its totient is φ = 211233360033024.

The previous prime is 644634124613627. The next prime is 644634124613669. The reversal of 644634124613664 is 466316421436446.

It is a tau number, because it is divible by the number of its divisors (96).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 644634124613598 and 644634124613607.

It is not an unprimeable number, because it can be changed into a prime (644634124613669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 473050917 + ... + 474411675.

It is an arithmetic number, because the mean of its divisors is an integer number (17925699708000).

Almost surely, 2^{644634124613664} is an apocalyptic number.

It is an amenable number.

644634124613664 is an abundant number, since it is smaller than the sum of its proper divisors (1076233047354336).

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

644634124613664 is a wasteful number, since it uses less digits than its factorization.

644634124613664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1444470 (or 1444462 counting only the distinct ones).

The product of its digits is 143327232, while the sum is 60.

The spelling of 644634124613664 in words is "six hundred forty-four trillion, six hundred thirty-four billion, one hundred twenty-four million, six hundred thirteen thousand, six hundred sixty-four".