663664 has 10 divisors (see below), whose sum is σ = 1285880. Its totient is φ = 331824.

The previous prime is 663661. The next prime is 663683. The reversal of 663664 is 466366.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20724 + ... + 20755.

It is an arithmetic number, because the mean of its divisors is an integer number (128588).

2⁶⁶³⁶⁶⁴ is an apocalyptic number.

It is an amenable number.

663664 is a deficient number, since it is larger than the sum of its proper divisors (622216).

663664 is a wasteful number, since it uses less digits than its factorization.

663664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41487 (or 41481 counting only the distinct ones).

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

The square root of 663664 is about 814.6557555189. The cubic root of 663664 is about 87.2266955271.

The spelling of 663664 in words is "six hundred sixty-three thousand, six hundred sixty-four".