81427 has 4 divisors (see below), whose sum is σ = 82296. Its totient is φ = 80560.

The previous prime is 81421. The next prime is 81439. The reversal of 81427 is 72418.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 72418 = 2 ⋅36209.

It is a cyclic number.

It is not a de Polignac number, because 81427 - 2⁷ = 81299 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81398 and 81407.

It is not an unprimeable number, because it can be changed into a prime (81421) 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, 274 + ... + 487.

It is an arithmetic number, because the mean of its divisors is an integer number (20574).

2⁸¹⁴²⁷ is an apocalyptic number.

81427 is a deficient number, since it is larger than the sum of its proper divisors (869).

81427 is a wasteful number, since it uses less digits than its factorization.

81427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 868.

The product of its digits is 448, while the sum is 22.

The square root of 81427 is about 285.3541659062. The cubic root of 81427 is about 43.3433835992.

Subtracting from 81427 its reverse (72418), we obtain a palindrome (9009).

It can be divided in two parts, 814 and 27, that added together give a square (841 = 29²).

The spelling of 81427 in words is "eighty-one thousand, four hundred twenty-seven".