644272596 has 384 divisors, whose sum is σ = 2148249600. Its totient is φ = 164229120.

The previous prime is 644272589. The next prime is 644272609. The reversal of 644272596 is 695272446.

644272596 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 8825616 + ... + 8825688.

It is an arithmetic number, because the mean of its divisors is an integer number (5594400).

Almost surely, 2^644272596 is an apocalyptic number.

644272596 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644272596, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1074124800).

644272596 is an abundant number, since it is smaller than the sum of its proper divisors (1503977004).

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

644272596 is a wasteful number, since it uses less digits than its factorization.

644272596 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156 (or 148 counting only the distinct ones).

The product of its digits is 725760, while the sum is 45.

The square root of 644272596 is about 25382.5254062711. The cubic root of 644272596 is about 863.6873386435.

The spelling of 644272596 in words is "six hundred forty-four million, two hundred seventy-two thousand, five hundred ninety-six".