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18085 = 53617
BaseRepresentation
bin100011010100101
3220210211
410122211
51034320
6215421
7103504
oct43245
926724
1018085
1112651
12a571
138302
14683b
15555a
hex46a5

18085 has 4 divisors (see below), whose sum is σ = 21708. Its totient is φ = 14464.

The previous prime is 18077. The next prime is 18089. The reversal of 18085 is 58081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58081 = 2412.

It can be written as a sum of positive squares in 2 ways, for example, as 2209 + 15876 = 47^2 + 126^2 .

It is a cyclic number.

It is not a de Polignac number, because 18085 - 23 = 18077 is a prime.

It is a Smith number, since the sum of its digits (22) 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 Duffinian number.

18085 is a lucky number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18089) 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, 1804 + ... + 1813.

It is an arithmetic number, because the mean of its divisors is an integer number (5427).

218085 is an apocalyptic number.

It is an amenable number.

18085 is a deficient number, since it is larger than the sum of its proper divisors (3623).

18085 is an equidigital number, since it uses as much as digits as its factorization.

18085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3622.

The product of its (nonzero) digits is 320, while the sum is 22.

The square root of 18085 is about 134.4804818552. The cubic root of 18085 is about 26.2486015884.

The spelling of 18085 in words is "eighteen thousand, eighty-five".

Divisors: 1 5 3617 18085