644326232 has 48 divisors (see below), whose sum is σ = 1377832680. Its totient is φ = 280121600.

The previous prime is 644326229. The next prime is 644326237. The reversal of 644326232 is 232623446.

644326232 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 not an unprimeable number, because it can be changed into a prime (644326237) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39632 + ... + 53472.

Almost surely, 2^644326232 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 644326232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (688916340).

644326232 is an abundant number, since it is smaller than the sum of its proper divisors (733506448).

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

644326232 is a wasteful number, since it uses less digits than its factorization.

644326232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13904 (or 13877 counting only the distinct ones).

The product of its digits is 41472, while the sum is 32.

The square root of 644326232 is about 25383.5819379378. The cubic root of 644326232 is about 863.7113054390.

Adding to 644326232 its reverse (232623446), we get a palindrome (876949678).

The spelling of 644326232 in words is "six hundred forty-four million, three hundred twenty-six thousand, two hundred thirty-two".