664432 has 20 divisors (see below), whose sum is σ = 1301256. Its totient is φ = 328640.

The previous prime is 664427. The next prime is 664441. The reversal of 664432 is 234466.

It is a plaindrome in base 9.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 664397 and 664406.

It is a congruent number.

It is an unprimeable number.

664432 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1938 + ... + 2254.

2⁶⁶⁴⁴³² is an apocalyptic number.

It is an amenable number.

664432 is a deficient number, since it is larger than the sum of its proper divisors (636824).

664432 is a wasteful number, since it uses less digits than its factorization.

664432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 456 (or 450 counting only the distinct ones).

The product of its digits is 3456, while the sum is 25.

The square root of 664432 is about 815.1269839724. The cubic root of 664432 is about 87.2603291521.

Adding to 664432 its reverse (234466), we get a palindrome (898898).

The spelling of 664432 in words is "six hundred sixty-four thousand, four hundred thirty-two".