664312 has 16 divisors (see below), whose sum is σ = 1359000. Its totient is φ = 301920.

The previous prime is 664289. The next prime is 664319. The reversal of 664312 is 213466.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a plaindrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664319) by changing a digit.

664312 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, 3687 + ... + 3862.

2⁶⁶⁴³¹² is an apocalyptic number.

It is an amenable number.

664312 is an abundant number, since it is smaller than the sum of its proper divisors (694688).

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

664312 is a wasteful number, since it uses less digits than its factorization.

664312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7566 (or 7562 counting only the distinct ones).

The product of its digits is 864, while the sum is 22.

The square root of 664312 is about 815.0533724855. The cubic root of 664312 is about 87.2550756072.

Adding to 664312 its reverse (213466), we get a palindrome (877778).

The spelling of 664312 in words is "six hundred sixty-four thousand, three hundred twelve".