644372822 has 16 divisors (see below), whose sum is σ = 982497600. Its totient is φ = 316904640.

The previous prime is 644372819. The next prime is 644372857. The reversal of 644372822 is 228273446.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34922 + ... + 50082.

It is an arithmetic number, because the mean of its divisors is an integer number (61406100).

Almost surely, 2^644372822 is an apocalyptic number.

644372822 is a deficient number, since it is larger than the sum of its proper divisors (338124778).

644372822 is a wasteful number, since it uses less digits than its factorization.

644372822 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15511.

The product of its digits is 129024, while the sum is 38.

The square root of 644372822 is about 25384.4996405287. The cubic root of 644372822 is about 863.7321227092.

The spelling of 644372822 in words is "six hundred forty-four million, three hundred seventy-two thousand, eight hundred twenty-two".