644304 has 40 divisors (see below), whose sum is σ = 1722112. Its totient is φ = 207360.

The previous prime is 644297. The next prime is 644327. The reversal of 644304 is 403446.

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, 1272 + ... + 1704.

2⁶⁴⁴³⁰⁴ 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 644304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (861056).

644304 is an abundant number, since it is smaller than the sum of its proper divisors (1077808).

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

644304 is a wasteful number, since it uses less digits than its factorization.

644304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 475 (or 469 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 21.

The square root of 644304 is about 802.6854925810. The cubic root of 644304 is about 86.3701371418.

The spelling of 644304 in words is "six hundred forty-four thousand, three hundred four".