865144 has 24 divisors (see below), whose sum is σ = 1887840. Its totient is φ = 370608.

The previous prime is 865121. The next prime is 865153. The reversal of 865144 is 441568.

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

It is a congruent number.

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 5 ways as a sum of consecutive naturals, for example, 712 + ... + 1495.

It is an arithmetic number, because the mean of its divisors is an integer number (78660).

2⁸⁶⁵¹⁴⁴ is an apocalyptic number.

It is an amenable number.

865144 is an abundant number, since it is smaller than the sum of its proper divisors (1022696).

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

865144 is a wasteful number, since it uses less digits than its factorization.

865144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2227 (or 2216 counting only the distinct ones).

The product of its digits is 3840, while the sum is 28.

The square root of 865144 is about 930.1311735449. The cubic root of 865144 is about 95.2860813100.

The spelling of 865144 in words is "eight hundred sixty-five thousand, one hundred forty-four".