18065 has 4 divisors (see below), whose sum is σ = 21684. Its totient is φ = 14448.

The previous prime is 18061. The next prime is 18077. The reversal of 18065 is 56081.

18065 is nontrivially palindromic in base 4.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1936 + 16129 = 44^2 + 127^2 .

It is a cyclic number.

It is not a de Polignac number, because 18065 - 2² = 18061 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 8 and base 12.

It is not an unprimeable number, because it can be changed into a prime (18061) 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, 1802 + ... + 1811.

It is an arithmetic number, because the mean of its divisors is an integer number (5421).

2¹⁸⁰⁶⁵ is an apocalyptic number.

It is an amenable number.

18065 is a deficient number, since it is larger than the sum of its proper divisors (3619).

18065 is an equidigital number, since it uses as much as digits as its factorization.

18065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3618.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 18065 is about 134.4061010520. The cubic root of 18065 is about 26.2389220073.

The spelling of 18065 in words is "eighteen thousand, sixty-five".