644634500 has 48 divisors (see below), whose sum is σ = 1440671232. Its totient is φ = 251848800.

The previous prime is 644634499. The next prime is 644634511. The reversal of 644634500 is 5436446.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6509 + ... + 36491.

It is an arithmetic number, because the mean of its divisors is an integer number (30013984).

Almost surely, 2^644634500 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644634500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (720335616).

644634500 is an abundant number, since it is smaller than the sum of its proper divisors (796036732).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644634500 is a wasteful number, since it uses less digits than its factorization.

644634500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30045 (or 30033 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 32.

The square root of 644634500 is about 25389.6534044874. The cubic root of 644634500 is about 863.8490266186.

The spelling of 644634500 in words is "six hundred forty-four million, six hundred thirty-four thousand, five hundred".