81744 has 40 divisors (see below), whose sum is σ = 229152. Its totient is φ = 24960.

The previous prime is 81737. The next prime is 81749. The reversal of 81744 is 44718.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81749) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 559 + ... + 689.

2⁸¹⁷⁴⁴ 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 81744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114576).

81744 is an abundant number, since it is smaller than the sum of its proper divisors (147408).

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

81744 is a wasteful number, since it uses less digits than its factorization.

81744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155 (or 149 counting only the distinct ones).

The product of its digits is 896, while the sum is 24.

The square root of 81744 is about 285.9090764561. The cubic root of 81744 is about 43.3995568630.

It can be divided in two parts, 817 and 44, that added together give a triangular number (861 = T₄₁).

The spelling of 81744 in words is "eighty-one thousand, seven hundred forty-four".