656668 has 12 divisors (see below), whose sum is σ = 1156792. Its totient is φ = 326160.

The previous prime is 656657. The next prime is 656671. The reversal of 656668 is 866656.

It is a congruent number.

It is an unprimeable 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, 271 + ... + 1177.

2⁶⁵⁶⁶⁶⁸ is an apocalyptic number.

It is an amenable number.

656668 is a deficient number, since it is larger than the sum of its proper divisors (500124).

656668 is a wasteful number, since it uses less digits than its factorization.

656668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1092 (or 1090 counting only the distinct ones).

The product of its digits is 51840, while the sum is 37.

The square root of 656668 is about 810.3505414325. The cubic root of 656668 is about 86.9191127349.

The spelling of 656668 in words is "six hundred fifty-six thousand, six hundred sixty-eight".