644968096 has 24 divisors (see below), whose sum is σ = 1272529440. Its totient is φ = 321786048.

The previous prime is 644968069. The next prime is 644968133. The reversal of 644968096 is 690869446.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6636 + ... + 36523.

It is an arithmetic number, because the mean of its divisors is an integer number (53022060).

Almost surely, 2^644968096 is an apocalyptic number.

It is an amenable number.

644968096 is a deficient number, since it is larger than the sum of its proper divisors (627561344).

644968096 is a wasteful number, since it uses less digits than its factorization.

644968096 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43636 (or 43628 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 52.

The square root of 644968096 is about 25396.2220812467. Note that the first 3 decimals coincide. The cubic root of 644968096 is about 863.9980138272.

The spelling of 644968096 in words is "six hundred forty-four million, nine hundred sixty-eight thousand, ninety-six".