81424 has 20 divisors (see below), whose sum is σ = 180544. Its totient is φ = 34848.

The previous prime is 81421. The next prime is 81439. The reversal of 81424 is 42418.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (81421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 252 + ... + 475.

2⁸¹⁴²⁴ is an apocalyptic number.

It is an amenable number.

81424 is an abundant number, since it is smaller than the sum of its proper divisors (99120).

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 (90272).

81424 is a wasteful number, since it uses less digits than its factorization.

81424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 742 (or 736 counting only the distinct ones).

The product of its digits is 256, while the sum is 19.

The square root of 81424 is about 285.3489092322. The cubic root of 81424 is about 43.3428512952.

It can be divided in two parts, 814 and 24, that added together give a palindrome (838).

The spelling of 81424 in words is "eighty-one thousand, four hundred twenty-four".