81187 has 4 divisors (see below), whose sum is σ = 85480. Its totient is φ = 76896.

The previous prime is 81181. The next prime is 81197. The reversal of 81187 is 78118.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81187 - 2¹¹ = 79139 is a prime.

It is a Duffinian 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 3 ways as a sum of consecutive naturals, for example, 2118 + ... + 2155.

It is an arithmetic number, because the mean of its divisors is an integer number (21370).

2⁸¹¹⁸⁷ is an apocalyptic number.

81187 is a deficient number, since it is larger than the sum of its proper divisors (4293).

81187 is a wasteful number, since it uses less digits than its factorization.

81187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4292.

The product of its digits is 448, while the sum is 25.

The square root of 81187 is about 284.9333255342. The cubic root of 81187 is about 43.3007578979.

It can be divided in two parts, 811 and 87, that added together give a palindrome (898).

The spelling of 81187 in words is "eighty-one thousand, one hundred eighty-seven".