644332304 has 80 divisors (see below), whose sum is σ = 1624181760. Its totient is φ = 240113280.

The previous prime is 644332301. The next prime is 644332361. The reversal of 644332304 is 403233446.

644332304 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (644332301) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16967 + ... + 39705.

It is an arithmetic number, because the mean of its divisors is an integer number (20302272).

Almost surely, 2^644332304 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 644332304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (812090880).

644332304 is an abundant number, since it is smaller than the sum of its proper divisors (979849456).

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

644332304 is a wasteful number, since it uses less digits than its factorization.

644332304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22788 (or 22782 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 29.

The square root of 644332304 is about 25383.7015425253. The cubic root of 644332304 is about 863.7140185773.

The spelling of 644332304 in words is "six hundred forty-four million, three hundred thirty-two thousand, three hundred four".