664872 has 32 divisors (see below), whose sum is σ = 1790880. Its totient is φ = 204480.

The previous prime is 664849. The next prime is 664879. The reversal of 664872 is 278466.

It is not an unprimeable number, because it can be changed into a prime (664879) by changing a digit.

664872 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 754 + ... + 1377.

It is an arithmetic number, because the mean of its divisors is an integer number (55965).

2⁶⁶⁴⁸⁷² is an apocalyptic number.

It is an amenable number.

664872 is an abundant number, since it is smaller than the sum of its proper divisors (1126008).

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

664872 is a wasteful number, since it uses less digits than its factorization.

664872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2153 (or 2149 counting only the distinct ones).

The product of its digits is 16128, while the sum is 33.

The square root of 664872 is about 815.3968359026. The cubic root of 664872 is about 87.2795867399.

The spelling of 664872 in words is "six hundred sixty-four thousand, eight hundred seventy-two".