687864 has 16 divisors (see below), whose sum is σ = 1719720. Its totient is φ = 229280.

The previous prime is 687847. The next prime is 687893. The reversal of 687864 is 468786.

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 687864.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14307 + ... + 14354.

2⁶⁸⁷⁸⁶⁴ is an apocalyptic number.

It is an amenable number.

687864 is an abundant number, since it is smaller than the sum of its proper divisors (1031856).

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

687864 is a wasteful number, since it uses less digits than its factorization.

687864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28670 (or 28666 counting only the distinct ones).

The product of its digits is 64512, while the sum is 39.

The square root of 687864 is about 829.3756688015. The cubic root of 687864 is about 88.2742819598.

It can be divided in two parts, 687 and 864, that added together give a palindrome (1551).

The spelling of 687864 in words is "six hundred eighty-seven thousand, eight hundred sixty-four".