865444 has 18 divisors (see below), whose sum is σ = 1587110. Its totient is φ = 412896.

The previous prime is 865409. The next prime is 865457. The reversal of 865444 is 444568.

It can be written as a sum of positive squares in only one way, i.e., 846400 + 19044 = 920^2 + 138^2 .

It is an Ulam number.

It is a nialpdrome in base 10.

It is an unprimeable number.

865444 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 5 ways as a sum of consecutive naturals, for example, 1912 + ... + 2320.

2⁸⁶⁵⁴⁴⁴ is an apocalyptic number.

It is an amenable number.

865444 is a deficient number, since it is larger than the sum of its proper divisors (721666).

865444 is a wasteful number, since it uses less digits than its factorization.

865444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459 (or 434 counting only the distinct ones).

The product of its digits is 15360, while the sum is 31.

The square root of 865444 is about 930.2924271432. The cubic root of 865444 is about 95.2970939356.

Subtracting from 865444 its product of digits (15360), we obtain a square (850084 = 922²).

The spelling of 865444 in words is "eight hundred sixty-five thousand, four hundred forty-four".