664812 has 36 divisors (see below), whose sum is σ = 1714440. Its totient is φ = 217152.

The previous prime is 664799. The next prime is 664843. The reversal of 664812 is 218466.

664812 is a `hidden beast` number, since 6 + 648 + 12 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1968 + ... + 2280.

2⁶⁶⁴⁸¹² is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (857220).

664812 is an abundant number, since it is smaller than the sum of its proper divisors (1049628).

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

664812 is a wasteful number, since it uses less digits than its factorization.

664812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 382 (or 377 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 664812 is about 815.3600431711. The cubic root of 664812 is about 87.2769612056.

The spelling of 664812 in words is "six hundred sixty-four thousand, eight hundred twelve".