644054502 has 64 divisors (see below), whose sum is σ = 1612316160. Its totient is φ = 166973184.

The previous prime is 644054491. The next prime is 644054573. The reversal of 644054502 is 205450446.

It is a self number, because there is not a number n which added to its sum of digits gives 644054502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22218 + ... + 42210.

It is an arithmetic number, because the mean of its divisors is an integer number (25192440).

Almost surely, 2^644054502 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644054502, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (806158080).

644054502 is an abundant number, since it is smaller than the sum of its proper divisors (968261658).

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

644054502 is a wasteful number, since it uses less digits than its factorization.

644054502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20077.

The product of its (nonzero) digits is 19200, while the sum is 30.

The square root of 644054502 is about 25378.2288980141. The cubic root of 644054502 is about 863.5898714709.

The spelling of 644054502 in words is "six hundred forty-four million, fifty-four thousand, five hundred two".