687636 has 24 divisors (see below), whose sum is σ = 1783040. Its totient is φ = 229176.

The previous prime is 687623. The next prime is 687637. The reversal of 687636 is 636786.

It is a happy number.

687636 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 687636.

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 687636.

It is not an unprimeable number, because it can be changed into a prime (687637) by changing a digit.

687636 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3076 + ... + 3291.

2⁶⁸⁷⁶³⁶ is an apocalyptic number.

It is an amenable number.

687636 is an abundant number, since it is smaller than the sum of its proper divisors (1095404).

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

687636 is a wasteful number, since it uses less digits than its factorization.

687636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6380 (or 6372 counting only the distinct ones).

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

The square root of 687636 is about 829.2382046192. The cubic root of 687636 is about 88.2645277252.

The spelling of 687636 in words is "six hundred eighty-seven thousand, six hundred thirty-six".