665687 has 8 divisors (see below), whose sum is σ = 737040. Its totient is φ = 596160.

The previous prime is 665677. The next prime is 665713. The reversal of 665687 is 786566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 665687 - 2¹⁰ = 664663 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 665687.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665617) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 389 + ... + 1217.

It is an arithmetic number, because the mean of its divisors is an integer number (92130).

2⁶⁶⁵⁶⁸⁷ is an apocalyptic number.

665687 is a deficient number, since it is larger than the sum of its proper divisors (71353).

665687 is a wasteful number, since it uses less digits than its factorization.

665687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 913.

The product of its digits is 60480, while the sum is 38.

The square root of 665687 is about 815.8964395069. The cubic root of 665687 is about 87.3152346130.

The spelling of 665687 in words is "six hundred sixty-five thousand, six hundred eighty-seven".