81582 has 8 divisors (see below), whose sum is σ = 163176. Its totient is φ = 27192.

The previous prime is 81569. The next prime is 81611. The reversal of 81582 is 28518.

It is a sphenic number, since it is the product of 3 distinct primes.

81582 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6793 + ... + 6804.

It is an arithmetic number, because the mean of its divisors is an integer number (20397).

2⁸¹⁵⁸² is an apocalyptic number.

81582 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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 (81588).

81582 is a wasteful number, since it uses less digits than its factorization.

81582 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13602.

The product of its digits is 640, while the sum is 24.

The square root of 81582 is about 285.6256291022. The cubic root of 81582 is about 43.3708682015.

The spelling of 81582 in words is "eighty-one thousand, five hundred eighty-two".