81158 has 32 divisors (see below), whose sum is σ = 165888. Its totient is φ = 28800.

The previous prime is 81157. The next prime is 81163. The reversal of 81158 is 85118.

It is a Smith number, since the sum of its digits (23) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81157) 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, 2603 + ... + 2633.

It is an arithmetic number, because the mean of its divisors is an integer number (5184).

2⁸¹¹⁵⁸ is an apocalyptic number.

81158 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 (82944).

81158 is a wasteful number, since it uses less digits than its factorization.

81158 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68.

The product of its digits is 320, while the sum is 23.

The square root of 81158 is about 284.8824318908. The cubic root of 81158 is about 43.2956016063.

The spelling of 81158 in words is "eighty-one thousand, one hundred fifty-eight".