81844 has 24 divisors (see below), whose sum is σ = 170240. Its totient is φ = 33696.

The previous prime is 81839. The next prime is 81847. The reversal of 81844 is 44818.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81847) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 997 + ... + 1075.

2⁸¹⁸⁴⁴ 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 81844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85120).

81844 is an abundant number, since it is smaller than the sum of its proper divisors (88396).

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

81844 is a wasteful number, since it uses less digits than its factorization.

81844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127 (or 125 counting only the distinct ones).

The product of its digits is 1024, while the sum is 25.

The square root of 81844 is about 286.0839037765. The cubic root of 81844 is about 43.4172469978.

The spelling of 81844 in words is "eighty-one thousand, eight hundred forty-four".