644500966 has 16 divisors (see below), whose sum is σ = 972373248. Its totient is φ = 320382400.

The previous prime is 644500949. The next prime is 644500979. The reversal of 644500966 is 669005446.

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, 304251 + ... + 306361.

It is an arithmetic number, because the mean of its divisors is an integer number (60773328).

Almost surely, 2^644500966 is an apocalyptic number.

644500966 is a deficient number, since it is larger than the sum of its proper divisors (327872282).

644500966 is a wasteful number, since it uses less digits than its factorization.

644500966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2927.

The product of its (nonzero) digits is 155520, while the sum is 40.

The square root of 644500966 is about 25387.0235750472. The cubic root of 644500966 is about 863.7893746340.

The spelling of 644500966 in words is "six hundred forty-four million, five hundred thousand, nine hundred sixty-six".