644032 has 28 divisors (see below), whose sum is σ = 1325880. Its totient is φ = 310016.

The previous prime is 644029. The next prime is 644047. The reversal of 644032 is 230446.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1683 + ... + 2029.

2⁶⁴⁴⁰³² 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 644032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (662940).

644032 is an abundant number, since it is smaller than the sum of its proper divisors (681848).

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

644032 is a wasteful number, since it uses less digits than its factorization.

644032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 388 (or 378 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 644032 is about 802.5160434533. The cubic root of 644032 is about 86.3579813975.

Adding to 644032 its reverse (230446), we get a palindrome (874478).

It can be divided in two parts, 64 and 4032, that added together give a 12-th power (4096 = 2¹²).

The spelling of 644032 in words is "six hundred forty-four thousand, thirty-two".