865880 has 16 divisors (see below), whose sum is σ = 1948320. Its totient is φ = 346336.

The previous prime is 865877. The next prime is 865889. The reversal of 865880 is 88568.

865880 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 865880.

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 865880.

It is not an unprimeable number, because it can be changed into a prime (865889) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10784 + ... + 10863.

It is an arithmetic number, because the mean of its divisors is an integer number (121770).

2⁸⁶⁵⁸⁸⁰ is an apocalyptic number.

It is an amenable number.

865880 is an abundant number, since it is smaller than the sum of its proper divisors (1082440).

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

865880 is a wasteful number, since it uses less digits than its factorization.

865880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21658 (or 21654 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 35.

The square root of 865880 is about 930.5267325553. The cubic root of 865880 is about 95.3130944154.

The spelling of 865880 in words is "eight hundred sixty-five thousand, eight hundred eighty".