636664 has 16 divisors (see below), whose sum is σ = 1364400. Its totient is φ = 272832.

The previous prime is 636653. The next prime is 636673. The reversal of 636664 is 466636.

It is a congruent number.

It is an unprimeable number.

636664 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, 5629 + ... + 5740.

It is an arithmetic number, because the mean of its divisors is an integer number (85275).

2⁶³⁶⁶⁶⁴ is an apocalyptic number.

It is an amenable number.

636664 is an abundant number, since it is smaller than the sum of its proper divisors (727736).

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

636664 is a wasteful number, since it uses less digits than its factorization.

636664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11382 (or 11378 counting only the distinct ones).

The product of its digits is 15552, while the sum is 31.

The square root of 636664 is about 797.9122758800. The cubic root of 636664 is about 86.0273934729.

The spelling of 636664 in words is "six hundred thirty-six thousand, six hundred sixty-four".