81185 has 8 divisors (see below), whose sum is σ = 105000. Its totient is φ = 59904.

The previous prime is 81181. The next prime is 81197. The reversal of 81185 is 58118.

It can be written as a sum of positive squares in 4 ways, for example, as 529 + 80656 = 23^2 + 284^2 .

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

It is not a de Polignac number, because 81185 - 2² = 81181 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81185.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81181) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 560 + ... + 689.

It is an arithmetic number, because the mean of its divisors is an integer number (13125).

2⁸¹¹⁸⁵ is an apocalyptic number.

It is an amenable number.

81185 is a deficient number, since it is larger than the sum of its proper divisors (23815).

81185 is a wasteful number, since it uses less digits than its factorization.

81185 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1267.

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

The square root of 81185 is about 284.9298159196. The cubic root of 81185 is about 43.3004023310.

The spelling of 81185 in words is "eighty-one thousand, one hundred eighty-five".