866820 has 24 divisors (see below), whose sum is σ = 2427264. Its totient is φ = 231136.

The previous prime is 866819. The next prime is 866843. The reversal of 866820 is 28668.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 866820.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7164 + ... + 7283.

It is an arithmetic number, because the mean of its divisors is an integer number (101136).

2⁸⁶⁶⁸²⁰ is an apocalyptic number.

It is an amenable number.

866820 is an abundant number, since it is smaller than the sum of its proper divisors (1560444).

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

866820 is a wasteful number, since it uses less digits than its factorization.

866820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14459 (or 14457 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 866820 is about 931.0316858196. The cubic root of 866820 is about 95.3475725983.

The spelling of 866820 in words is "eight hundred sixty-six thousand, eight hundred twenty".