866656 has 48 divisors (see below), whose sum is σ = 2013984. Its totient is φ = 359424.

The previous prime is 866653. The next prime is 866683. The reversal of 866656 is 656668.

Its product of digits (51840) is a multiple of the sum of its prime divisors (135).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866653) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11836 + ... + 11908.

It is an arithmetic number, because the mean of its divisors is an integer number (41958).

2⁸⁶⁶⁶⁵⁶ 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 866656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1006992).

866656 is an abundant number, since it is smaller than the sum of its proper divisors (1147328).

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

866656 is a wasteful number, since it uses less digits than its factorization.

866656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143 (or 135 counting only the distinct ones).

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

The square root of 866656 is about 930.9436073146. The cubic root of 866656 is about 95.3415590514.

The spelling of 866656 in words is "eight hundred sixty-six thousand, six hundred fifty-six".