644408048 has 10 divisors (see below), whose sum is σ = 1248540624. Its totient is φ = 322204016.

The previous prime is 644408041. The next prime is 644408071. The reversal of 644408048 is 840804446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644408041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20137736 + ... + 20137767.

Almost surely, 2^644408048 is an apocalyptic number.

It is an amenable number.

644408048 is a deficient number, since it is larger than the sum of its proper divisors (604132576).

644408048 is a wasteful number, since it uses less digits than its factorization.

644408048 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40275511 (or 40275505 counting only the distinct ones).

The product of its (nonzero) digits is 98304, while the sum is 38.

The square root of 644408048 is about 25385.1934796645. The cubic root of 644408048 is about 863.7478616688.

The spelling of 644408048 in words is "six hundred forty-four million, four hundred eight thousand, forty-eight".