81943 has 2 divisors, whose sum is σ = 81944. Its totient is φ = 81942.

The previous prime is 81937. The next prime is 81953. The reversal of 81943 is 34918.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81943 - 2¹³ = 73751 is a prime.

81943 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40971 + 40972.

It is an arithmetic number, because the mean of its divisors is an integer number (40972).

2⁸¹⁹⁴³ is an apocalyptic number.

81943 is a deficient number, since it is larger than the sum of its proper divisors (1).

81943 is an equidigital number, since it uses as much as digits as its factorization.

81943 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 25.

The square root of 81943 is about 286.2568776466. The cubic root of 81943 is about 43.4347460428.

Subtracting from 81943 its sum of digits (25), we obtain a palindrome (81918).

It can be divided in two parts, 81 and 943, that added together give a 10-th power (1024 = 2¹⁰).

The spelling of 81943 in words is "eighty-one thousand, nine hundred forty-three".