865900 has 36 divisors (see below), whose sum is σ = 2149168. Its totient is φ = 296640.

The previous prime is 865889. The next prime is 865933. The reversal of 865900 is 9568.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 82 + ... + 1318.

2⁸⁶⁵⁹⁰⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 865900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1074584).

865900 is an abundant number, since it is smaller than the sum of its proper divisors (1283268).

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

865900 is a wasteful number, since it uses less digits than its factorization.

865900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1258 (or 1251 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 865900 is about 930.5374790947. The cubic root of 865900 is about 95.3138282535.

The spelling of 865900 in words is "eight hundred sixty-five thousand, nine hundred".