664806 has 16 divisors (see below), whose sum is σ = 1339200. Its totient is φ = 220008.

The previous prime is 664799. The next prime is 664843. The reversal of 664806 is 608466.

It is a happy number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 664806.

It is an unprimeable number.

664806 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 7 ways as a sum of consecutive naturals, for example, 765 + ... + 1383.

It is an arithmetic number, because the mean of its divisors is an integer number (83700).

2⁶⁶⁴⁸⁰⁶ is an apocalyptic number.

664806 is an abundant number, since it is smaller than the sum of its proper divisors (674394).

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

664806 is a wasteful number, since it uses less digits than its factorization.

664806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 803.

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 664806 is about 815.3563638066. The cubic root of 664806 is about 87.2766986435.

The spelling of 664806 in words is "six hundred sixty-four thousand, eight hundred six".