865904 has 40 divisors (see below), whose sum is σ = 1895712. Its totient is φ = 380160.

The previous prime is 865889. The next prime is 865933. The reversal of 865904 is 409568.

865904 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

865904 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, 4694 + ... + 4874.

2⁸⁶⁵⁹⁰⁴ 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 865904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (947856).

865904 is an abundant number, since it is smaller than the sum of its proper divisors (1029808).

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

865904 is a wasteful number, since it uses less digits than its factorization.

865904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225 (or 219 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 865904 is about 930.5396283877. The cubic root of 865904 is about 95.3139750197.

The spelling of 865904 in words is "eight hundred sixty-five thousand, nine hundred four".