6687 has 6 divisors (see below), whose sum is σ = 9672.
Its totient is φ = 4452.
The previous prime is 6679. The next prime is 6689. The reversal of 6687 is 7866.
It can be divided in two parts, 66 and 87, that added together give a triangular number (153 = T17).
It is not a de Polignac number, because 6687 - 23 = 6679 is a prime.
6687 is a lucky number.
It is a self number, because there is not a number n which added to its sum of digits gives 6687.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (6689) by changing a digit.
It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 363 + ... + 380.
It is an arithmetic number, because the mean of its divisors is an integer number (1612).
26687 is an apocalyptic number.
6687 is a deficient number, since it is larger than the sum of its proper divisors (2985).
6687 is a wasteful number, since it uses less digits than its factorization.
6687 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 749 (or 746 counting only the distinct ones).
The product of its digits is 2016, while the sum is 27.
The square root of 6687 is about 81.7740790226.
The cubic root of 6687 is about 18.8398355565.
The spelling of 6687 in words is "six thousand, six hundred eighty-seven".