81543 has 16 divisors (see below), whose sum is σ = 135936. Its totient is φ = 42240.

The previous prime is 81533. The next prime is 81547. The reversal of 81543 is 34518.

It is not a de Polignac number, because 81543 - 2⁴ = 81527 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81547) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55 + ... + 407.

It is an arithmetic number, because the mean of its divisors is an integer number (8496).

2⁸¹⁵⁴³ is an apocalyptic number.

81543 is a deficient number, since it is larger than the sum of its proper divisors (54393).

81543 is a wasteful number, since it uses less digits than its factorization.

81543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 374.

The product of its digits is 480, while the sum is 21.

The square root of 81543 is about 285.5573497566. The cubic root of 81543 is about 43.3639560009.

81543 divided by its sum of digits (21) gives a palindrome (3883).

It can be divided in two parts, 815 and 43, that added together give a palindrome (858).

The spelling of 81543 in words is "eighty-one thousand, five hundred forty-three".