664636 has 18 divisors (see below), whose sum is σ = 1353408. Its totient is φ = 284760.

The previous prime is 664633. The next prime is 664661. The reversal of 664636 is 636466.

It is a junction number, because it is equal to n+sod(n) for n = 664598 and 664607.

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 664636.

It is not an unprimeable number, because it can be changed into a prime (664633) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1500 + ... + 1891.

2⁶⁶⁴⁶³⁶ is an apocalyptic number.

It is an amenable number.

664636 is an abundant number, since it is smaller than the sum of its proper divisors (688772).

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

664636 is a wasteful number, since it uses less digits than its factorization.

664636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3409 (or 3400 counting only the distinct ones).

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

The square root of 664636 is about 815.2521082463. The cubic root of 664636 is about 87.2692587268.

The spelling of 664636 in words is "six hundred sixty-four thousand, six hundred thirty-six".