81843 has 4 divisors (see below), whose sum is σ = 109128. Its totient is φ = 54560.

The previous prime is 81839. The next prime is 81847. The reversal of 81843 is 34818.

81843 is an esthetic number in base 11, because in such base its adjacent digits differ by 1.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (81839) and next prime (81847).

It is a cyclic number.

It is not a de Polignac number, because 81843 - 2² = 81839 is a prime.

It is a D-number.

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

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13638 + ... + 13643.

It is an arithmetic number, because the mean of its divisors is an integer number (27282).

2⁸¹⁸⁴³ is an apocalyptic number.

81843 is a deficient number, since it is larger than the sum of its proper divisors (27285).

81843 is a wasteful number, since it uses less digits than its factorization.

81843 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27284.

The product of its digits is 768, while the sum is 24.

The square root of 81843 is about 286.0821560321. The cubic root of 81843 is about 43.4170701678.

It can be divided in two parts, 818 and 43, that added together give a triangular number (861 = T₄₁).

The spelling of 81843 in words is "eighty-one thousand, eight hundred forty-three".