856668 has 12 divisors (see below), whose sum is σ = 1998920. Its totient is φ = 285552.

The previous prime is 856649. The next prime is 856693. The reversal of 856668 is 866658.

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

It is a congruent number.

It is an unprimeable number.

856668 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, 35683 + ... + 35706.

2⁸⁵⁶⁶⁶⁸ is an apocalyptic number.

It is an amenable number.

856668 is an abundant number, since it is smaller than the sum of its proper divisors (1142252).

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

856668 is a wasteful number, since it uses less digits than its factorization.

856668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71396 (or 71394 counting only the distinct ones).

The product of its digits is 69120, while the sum is 39.

The square root of 856668 is about 925.5636120764. The cubic root of 856668 is about 94.9738801691.

The spelling of 856668 in words is "eight hundred fifty-six thousand, six hundred sixty-eight".