688660 has 24 divisors (see below), whose sum is σ = 1653120. Its totient is φ = 236064.

The previous prime is 688657. The next prime is 688661. The reversal of 688660 is 66886.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2320 + ... + 2599.

It is an arithmetic number, because the mean of its divisors is an integer number (68880).

2⁶⁸⁸⁶⁶⁰ is an apocalyptic number.

It is an amenable number.

688660 is an abundant number, since it is smaller than the sum of its proper divisors (964460).

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

688660 is a wasteful number, since it uses less digits than its factorization.

688660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4935 (or 4933 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 688660 is about 829.8554090925. The cubic root of 688660 is about 88.3083193284.

The spelling of 688660 in words is "six hundred eighty-eight thousand, six hundred sixty".