644926630 has 16 divisors (see below), whose sum is σ = 1162147680. Its totient is φ = 257686272.

The previous prime is 644926591. The next prime is 644926649. The reversal of 644926630 is 36629446.

It is a zygodrome in base 3.

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, 25899 + ... + 44278.

It is an arithmetic number, because the mean of its divisors is an integer number (72634230).

Almost surely, 2^644926630 is an apocalyptic number.

644926630 is a deficient number, since it is larger than the sum of its proper divisors (517221050).

644926630 is a wasteful number, since it uses less digits than its factorization.

644926630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71103.

The product of its (nonzero) digits is 186624, while the sum is 40.

The square root of 644926630 is about 25395.4056868560. The cubic root of 644926630 is about 863.9794975059.

The spelling of 644926630 in words is "six hundred forty-four million, nine hundred twenty-six thousand, six hundred thirty".