644133368 has 16 divisors (see below), whose sum is σ = 1210625160. Its totient is φ = 321300000.

The previous prime is 644133353. The next prime is 644133389. The reversal of 644133368 is 863331446.

644133368 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 an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 92258 + ... + 98993.

Almost surely, 2^644133368 is an apocalyptic number.

It is an amenable number.

644133368 is a deficient number, since it is larger than the sum of its proper divisors (566491792).

644133368 is a wasteful number, since it uses less digits than its factorization.

644133368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191678 (or 191674 counting only the distinct ones).

The product of its digits is 124416, while the sum is 38.

The square root of 644133368 is about 25379.7826625840. The cubic root of 644133368 is about 863.6251195743.

The spelling of 644133368 in words is "six hundred forty-four million, one hundred thirty-three thousand, three hundred sixty-eight".