687688 has 16 divisors (see below), whose sum is σ = 1309680. Its totient is φ = 338448.

The previous prime is 687683. The next prime is 687691. The reversal of 687688 is 886786.

It is a happy number.

687688 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (687683) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106 + ... + 1177.

It is an arithmetic number, because the mean of its divisors is an integer number (81855).

2⁶⁸⁷⁶⁸⁸ is an apocalyptic number.

It is an amenable number.

687688 is a deficient number, since it is larger than the sum of its proper divisors (621992).

687688 is a wasteful number, since it uses less digits than its factorization.

687688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1356 (or 1352 counting only the distinct ones).

The product of its digits is 129024, while the sum is 43.

The square root of 687688 is about 829.2695581052. The cubic root of 687688 is about 88.2667525650.

The spelling of 687688 in words is "six hundred eighty-seven thousand, six hundred eighty-eight".