663687 has 16 divisors (see below), whose sum is σ = 1006080. Its totient is φ = 432216.

The previous prime is 663683. The next prime is 663709. The reversal of 663687 is 786366.

It is a happy number.

It is not a de Polignac number, because 663687 - 2² = 663683 is a prime.

It is a super-3 number, since 3×663687³ = 877023413338751109, which contains 333 as substring.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1008 + ... + 1530.

It is an arithmetic number, because the mean of its divisors is an integer number (62880).

2⁶⁶³⁶⁸⁷ is an apocalyptic number.

663687 is a deficient number, since it is larger than the sum of its proper divisors (342393).

663687 is a wasteful number, since it uses less digits than its factorization.

663687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 579 (or 573 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 663687 is about 814.6698717886. The cubic root of 663687 is about 87.2277031609.

It can be divided in two parts, 66 and 3687, that multiplied together give a palindrome (243342).

The spelling of 663687 in words is "six hundred sixty-three thousand, six hundred eighty-seven".