865844 has 36 divisors (see below), whose sum is σ = 1856736. Its totient is φ = 345984.

The previous prime is 865829. The next prime is 865847. The reversal of 865844 is 448568.

865844 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (865847) by changing a digit.

865844 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 11 ways as a sum of consecutive naturals, for example, 8039 + ... + 8145.

It is an arithmetic number, because the mean of its divisors is an integer number (51576).

2⁸⁶⁵⁸⁴⁴ 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 865844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (928368).

865844 is an abundant number, since it is smaller than the sum of its proper divisors (990892).

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

865844 is a wasteful number, since it uses less digits than its factorization.

865844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152 (or 133 counting only the distinct ones).

The product of its digits is 30720, while the sum is 35.

The square root of 865844 is about 930.5073884715. The cubic root of 865844 is about 95.3117734783.

The spelling of 865844 in words is "eight hundred sixty-five thousand, eight hundred forty-four".