856656 has 50 divisors (see below), whose sum is σ = 2483162. Its totient is φ = 285120.

The previous prime is 856649. The next prime is 856693. The reversal of 856656 is 656658.

It can be written as a sum of positive squares in only one way, i.e., 810000 + 46656 = 900^2 + 216^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 856656.

It is a congruent number.

It is an unprimeable number.

856656 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 9 ways as a sum of consecutive naturals, for example, 966 + ... + 1626.

2⁸⁵⁶⁶⁵⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 856656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1241581).

856656 is an abundant number, since it is smaller than the sum of its proper divisors (1626506).

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

856656 is a wasteful number, since it uses less digits than its factorization.

856656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 681 (or 666 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 856656 is about 925.5571295171. The cubic root of 856656 is about 94.9734367099.

The spelling of 856656 in words is "eight hundred fifty-six thousand, six hundred fifty-six".