687656 has 16 divisors (see below), whose sum is σ = 1320000. Its totient is φ = 335664.

The previous prime is 687647. The next prime is 687679. The reversal of 687656 is 656786.

687656 = T₈₁ + T₈₂ + ... + T₁₆₆.

687656 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 656 + ... + 1343.

It is an arithmetic number, because the mean of its divisors is an integer number (82500).

2⁶⁸⁷⁶⁵⁶ is an apocalyptic number.

It is an amenable number.

687656 is a deficient number, since it is larger than the sum of its proper divisors (632344).

687656 is a wasteful number, since it uses less digits than its factorization.

687656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2048 (or 2044 counting only the distinct ones).

The product of its digits is 60480, while the sum is 38.

The square root of 687656 is about 829.2502637925. The cubic root of 687656 is about 88.2653834461.

The spelling of 687656 in words is "six hundred eighty-seven thousand, six hundred fifty-six".