865812 has 24 divisors (see below), whose sum is σ = 2108736. Its totient is φ = 275968.

The previous prime is 865807. The next prime is 865817. The reversal of 865812 is 218568.

It is an interprime number because it is at equal distance from previous prime (865807) and next prime (865817).

It is a self number, because there is not a number n which added to its sum of digits gives 865812.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 865812.

It is not an unprimeable number, because it can be changed into a prime (865817) by changing a digit.

865812 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, 1293 + ... + 1844.

It is an arithmetic number, because the mean of its divisors is an integer number (87864).

2⁸⁶⁵⁸¹² is an apocalyptic number.

It is an amenable number.

865812 is an abundant number, since it is smaller than the sum of its proper divisors (1242924).

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

865812 is a wasteful number, since it uses less digits than its factorization.

865812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3167 (or 3165 counting only the distinct ones).

The product of its digits is 3840, while the sum is 30.

The square root of 865812 is about 930.4901933927. The cubic root of 865812 is about 95.3105992813.

The spelling of 865812 in words is "eight hundred sixty-five thousand, eight hundred twelve".