656680 has 16 divisors (see below), whose sum is σ = 1477620. Its totient is φ = 262656.

The previous prime is 656671. The next prime is 656681. The reversal of 656680 is 86656.

It can be written as a sum of positive squares in 2 ways, for example, as 630436 + 26244 = 794^2 + 162^2 .

It is not an unprimeable number, because it can be changed into a prime (656681) by changing a digit.

656680 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, 8169 + ... + 8248.

2⁶⁵⁶⁶⁸⁰ is an apocalyptic number.

It is an amenable number.

656680 is an abundant number, since it is smaller than the sum of its proper divisors (820940).

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

656680 is a wasteful number, since it uses less digits than its factorization.

656680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16428 (or 16424 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 656680 is about 810.3579456018. The cubic root of 656680 is about 86.9196421871.

The spelling of 656680 in words is "six hundred fifty-six thousand, six hundred eighty".