891144 has 24 divisors (see below), whose sum is σ = 2413710. Its totient is φ = 297024.

The previous prime is 891133. The next prime is 891151. The reversal of 891144 is 441198.

It can be written as a sum of positive squares in only one way, i.e., 864900 + 26244 = 930^2 + 162^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a nude number because it is divisible by every one of its digits.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 891144.

It is an unprimeable number.

891144 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, 6117 + ... + 6260.

891144 is a Friedman number, since it can be written as 944^(1+1)+8, using all its digits and the basic arithmetic operations.

2⁸⁹¹¹⁴⁴ is an apocalyptic number.

It is an amenable number.

891144 is an abundant number, since it is smaller than the sum of its proper divisors (1522566).

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

891144 is a wasteful number, since it uses less digits than its factorization.

891144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12389 (or 12382 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 891144 is about 944.0042372786. The cubic root of 891144 is about 96.2312135145.

It can be divided in two parts, 891 and 144, that added together give a triangular number (1035 = T₄₅).

The spelling of 891144 in words is "eight hundred ninety-one thousand, one hundred forty-four".