644789322 has 24 divisors (see below), whose sum is σ = 1448786976. Its totient is φ = 214929612.

The previous prime is 644789293. The next prime is 644789351. The reversal of 644789322 is 223987446.

644789322 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (644789293) and next prime (644789351).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 662878 + ... + 663849.

It is an arithmetic number, because the mean of its divisors is an integer number (60366124).

Almost surely, 2^644789322 is an apocalyptic number.

644789322 is an abundant number, since it is smaller than the sum of its proper divisors (803997654).

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

644789322 is a wasteful number, since it uses less digits than its factorization.

644789322 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1326744 (or 1326732 counting only the distinct ones).

The product of its digits is 580608, while the sum is 45.

The square root of 644789322 is about 25392.7021405757. The cubic root of 644789322 is about 863.9181780155.

The spelling of 644789322 in words is "six hundred forty-four million, seven hundred eighty-nine thousand, three hundred twenty-two".