81942 has 16 divisors (see below), whose sum is σ = 187392. Its totient is φ = 23400.

The previous prime is 81937. The next prime is 81943. The reversal of 81942 is 24918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 934 + ... + 1017.

It is an arithmetic number, because the mean of its divisors is an integer number (11712).

2⁸¹⁹⁴² is an apocalyptic number.

81942 is an abundant number, since it is smaller than the sum of its proper divisors (105450).

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 (93696).

81942 is a wasteful number, since it uses less digits than its factorization.

81942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1963.

The product of its digits is 576, while the sum is 24.

The square root of 81942 is about 286.2551309584. The cubic root of 81942 is about 43.4345693553.

Subtracting from 81942 its sum of digits (24), we obtain a palindrome (81918).

It can be divided in two parts, 819 and 42, that added together give a triangular number (861 = T₄₁).

The spelling of 81942 in words is "eighty-one thousand, nine hundred forty-two".