644765144032 has 48 divisors (see below), whose sum is σ = 1271361256704. Its totient is φ = 321880176000.

The previous prime is 644765144027. The next prime is 644765144033. The reversal of 644765144032 is 230441567446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644765144033) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60303807 + ... + 60314497.

It is an arithmetic number, because the mean of its divisors is an integer number (26486692848).

Almost surely, 2^644765144032 is an apocalyptic number.

It is an amenable number.

644765144032 is a deficient number, since it is larger than the sum of its proper divisors (626596112672).

644765144032 is a wasteful number, since it uses less digits than its factorization.

644765144032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13463 (or 13455 counting only the distinct ones).

The product of its (nonzero) digits is 1935360, while the sum is 46.

The spelling of 644765144032 in words is "six hundred forty-four billion, seven hundred sixty-five million, one hundred forty-four thousand, thirty-two".