644793628724 has 48 divisors (see below), whose sum is σ = 1321528483968. Its totient is φ = 269514580608.

The previous prime is 644793628621. The next prime is 644793628819. The reversal of 644793628724 is 427826397446.

It is a congruent number.

It is an unprimeable number.

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, 419582 + ... + 1210634.

It is an arithmetic number, because the mean of its divisors is an integer number (27531843416).

Almost surely, 2^644793628724 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644793628724, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (660764241984).

644793628724 is an abundant number, since it is smaller than the sum of its proper divisors (676734855244).

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

644793628724 is a wasteful number, since it uses less digits than its factorization.

644793628724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 791784 (or 791782 counting only the distinct ones).

The product of its digits is 97542144, while the sum is 62.

The spelling of 644793628724 in words is "six hundred forty-four billion, seven hundred ninety-three million, six hundred twenty-eight thousand, seven hundred twenty-four".