656556 has 12 divisors (see below), whose sum is σ = 1531992. Its totient is φ = 218848.

The previous prime is 656527. The next prime is 656561. The reversal of 656556 is 655656.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×656556² = 862131562272, which contains 22 as substring.

It is an unprimeable number.

656556 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27345 + ... + 27368.

It is an arithmetic number, because the mean of its divisors is an integer number (127666).

2⁶⁵⁶⁵⁵⁶ is an apocalyptic number.

It is an amenable number.

656556 is an abundant number, since it is smaller than the sum of its proper divisors (875436).

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

656556 is a wasteful number, since it uses less digits than its factorization.

656556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54720 (or 54718 counting only the distinct ones).

The product of its digits is 27000, while the sum is 33.

The square root of 656556 is about 810.2814325899. The cubic root of 656556 is about 86.9141708697.

Subtracting from 656556 its reverse (655656), we obtain a square (900 = 30²).

The spelling of 656556 in words is "six hundred fifty-six thousand, five hundred fifty-six".