663996 has 12 divisors (see below), whose sum is σ = 1549352. Its totient is φ = 221328.

The previous prime is 663991. The next prime is 663997. The reversal of 663996 is 699366.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27655 + ... + 27678.

2⁶⁶³⁹⁹⁶ is an apocalyptic number.

It is an amenable number.

663996 is an abundant number, since it is smaller than the sum of its proper divisors (885356).

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

663996 is a wasteful number, since it uses less digits than its factorization.

663996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55340 (or 55338 counting only the distinct ones).

The product of its digits is 52488, while the sum is 39.

The square root of 663996 is about 814.8594970914. The cubic root of 663996 is about 87.2412382452.

The spelling of 663996 in words is "six hundred sixty-three thousand, nine hundred ninety-six".