866866 has 32 divisors (see below), whose sum is σ = 1749888. Its totient is φ = 311040.

The previous prime is 866857. The next prime is 866869. The reversal of 866866 is 668668.

866866 = 49² + 50² + ... + 139².

866866 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (866869) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1786 + ... + 2218.

It is an arithmetic number, because the mean of its divisors is an integer number (54684).

2⁸⁶⁶⁸⁶⁶ is an apocalyptic number.

866866 is an abundant number, since it is smaller than the sum of its proper divisors (883022).

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

866866 is a wasteful number, since it uses less digits than its factorization.

866866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 466.

The product of its digits is 82944, while the sum is 40.

The square root of 866866 is about 931.0563892697. The cubic root of 866866 is about 95.3492591886.

The spelling of 866866 in words is "eight hundred sixty-six thousand, eight hundred sixty-six".