663804 has 18 divisors (see below), whose sum is σ = 1678040. Its totient is φ = 221256.

The previous prime is 663797. The next prime is 663821. The reversal of 663804 is 408366.

It is a tau number, because it is divible by the number of its divisors (18).

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 663804.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9184 + ... + 9255.

2⁶⁶³⁸⁰⁴ is an apocalyptic number.

It is an amenable number.

663804 is an abundant number, since it is smaller than the sum of its proper divisors (1014236).

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

663804 is a wasteful number, since it uses less digits than its factorization.

663804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18449 (or 18444 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 663804 is about 814.7416768522. The cubic root of 663804 is about 87.2328285899.

The spelling of 663804 in words is "six hundred sixty-three thousand, eight hundred four".