687868 has 12 divisors (see below), whose sum is σ = 1209600. Its totient is φ = 342272.

The previous prime is 687847. The next prime is 687893. The reversal of 687868 is 868786.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

687868 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 3 ways as a sum of consecutive naturals, for example, 1308 + ... + 1756.

It is an arithmetic number, because the mean of its divisors is an integer number (100800).

2⁶⁸⁷⁸⁶⁸ is an apocalyptic number.

It is an amenable number.

687868 is a deficient number, since it is larger than the sum of its proper divisors (521732).

687868 is a wasteful number, since it uses less digits than its factorization.

687868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 836 (or 834 counting only the distinct ones).

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

The square root of 687868 is about 829.3780802505. The cubic root of 687868 is about 88.2744530674.

The spelling of 687868 in words is "six hundred eighty-seven thousand, eight hundred sixty-eight".