664528 has 20 divisors (see below), whose sum is σ = 1320228. Its totient is φ = 323840.

The previous prime is 664511. The next prime is 664529. The reversal of 664528 is 825466.

It can be written as a sum of positive squares in 2 ways, for example, as 11664 + 652864 = 108^2 + 808^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 664528.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664529) by changing a digit.

664528 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, 150 + ... + 1162.

2⁶⁶⁴⁵²⁸ is an apocalyptic number.

It is an amenable number.

664528 is a deficient number, since it is larger than the sum of its proper divisors (655700).

664528 is a wasteful number, since it uses less digits than its factorization.

664528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1062 (or 1056 counting only the distinct ones).

The product of its digits is 11520, while the sum is 31.

The square root of 664528 is about 815.1858683760. The cubic root of 664528 is about 87.2645315326.

The spelling of 664528 in words is "six hundred sixty-four thousand, five hundred twenty-eight".