644217275504 has 20 divisors (see below), whose sum is σ = 1361641059960. Its totient is φ = 292826034240.

The previous prime is 644217275497. The next prime is 644217275509. The reversal of 644217275504 is 405572712446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644217275509) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1830162539 + ... + 1830162890.

It is an arithmetic number, because the mean of its divisors is an integer number (68082052998).

Almost surely, 2^644217275504 is an apocalyptic number.

It is an amenable number.

644217275504 is an abundant number, since it is smaller than the sum of its proper divisors (717423784456).

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

644217275504 is a wasteful number, since it uses less digits than its factorization.

644217275504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3660325448 (or 3660325442 counting only the distinct ones).

The product of its (nonzero) digits is 1881600, while the sum is 47.

The spelling of 644217275504 in words is "six hundred forty-four billion, two hundred seventeen million, two hundred seventy-five thousand, five hundred four".