866856 has 32 divisors (see below), whose sum is σ = 2282400. Its totient is φ = 273600.

The previous prime is 866851. The next prime is 866857. The reversal of 866856 is 658668.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 866856.

It is not an unprimeable number, because it can be changed into a prime (866851) by changing a digit.

866856 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 7 ways as a sum of consecutive naturals, for example, 495 + ... + 1406.

It is an arithmetic number, because the mean of its divisors is an integer number (71325).

2⁸⁶⁶⁸⁵⁶ is an apocalyptic number.

It is an amenable number.

866856 is an abundant number, since it is smaller than the sum of its proper divisors (1415544).

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

866856 is a wasteful number, since it uses less digits than its factorization.

866856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1929 (or 1925 counting only the distinct ones).

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

The square root of 866856 is about 931.0510190102. The cubic root of 866856 is about 95.3488925436.

The spelling of 866856 in words is "eight hundred sixty-six thousand, eight hundred fifty-six".