644332 has 12 divisors (see below), whose sum is σ = 1214416. Its totient is φ = 297360.

The previous prime is 644327. The next prime is 644341. The reversal of 644332 is 233446.

It is a hoax number, since the sum of its digits (22) coincides with the sum of the digits of its distinct prime factors.

It is a nialpdrome in base 10.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6144 + ... + 6247.

2⁶⁴⁴³³² is an apocalyptic number.

It is an amenable number.

644332 is a deficient number, since it is larger than the sum of its proper divisors (570084).

644332 is a wasteful number, since it uses less digits than its factorization.

644332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12408 (or 12406 counting only the distinct ones).

The product of its digits is 1728, while the sum is 22.

The square root of 644332 is about 802.7029338429. The cubic root of 644332 is about 86.3713882742.

Adding to 644332 its reverse (233446), we get a palindrome (877778).

The spelling of 644332 in words is "six hundred forty-four thousand, three hundred thirty-two".