865656 has 48 divisors (see below), whose sum is σ = 2559960. Its totient is φ = 262080.

The previous prime is 865643. The next prime is 865661. The reversal of 865656 is 656568.

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 865656.

It is a congruent number.

It is an unprimeable number.

865656 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 (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 246 + ... + 1338.

2⁸⁶⁵⁶⁵⁶ 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 865656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1279980).

865656 is an abundant number, since it is smaller than the sum of its proper divisors (1694304).

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

865656 is a wasteful number, since it uses less digits than its factorization.

865656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1116 (or 1109 counting only the distinct ones).

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

The square root of 865656 is about 930.4063628329. The cubic root of 865656 is about 95.3048746565.

It can be divided in two parts, 865 and 656, that added together give a square (1521 = 39²).

The spelling of 865656 in words is "eight hundred sixty-five thousand, six hundred fifty-six".