81444 has 24 divisors (see below), whose sum is σ = 207648. Its totient is φ = 24640.

The previous prime is 81439. The next prime is 81457. The reversal of 81444 is 44418.

81444 is an esthetic number in base 5, because in such base its adjacent digits differ by 1.

It is a hoax number, since the sum of its digits (21) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 81444.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 177 + ... + 440.

It is an arithmetic number, because the mean of its divisors is an integer number (8652).

2⁸¹⁴⁴⁴ is an apocalyptic number.

It is an amenable number.

81444 is an abundant number, since it is smaller than the sum of its proper divisors (126204).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103824).

81444 is a wasteful number, since it uses less digits than its factorization.

81444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 635 (or 633 counting only the distinct ones).

The product of its digits is 512, while the sum is 21.

The square root of 81444 is about 285.3839518964. The cubic root of 81444 is about 43.3463997414.

It can be divided in two parts, 814 and 44, that added together give a palindrome (858).

The spelling of 81444 in words is "eighty-one thousand, four hundred forty-four".