20118 has 16 divisors (see below), whose sum is σ = 46080. Its totient is φ = 5736.

The previous prime is 20117. The next prime is 20123. The reversal of 20118 is 81102.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20113) 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, 198 + ... + 281.

It is an arithmetic number, because the mean of its divisors is an integer number (2880).

2²⁰¹¹⁸ is an apocalyptic number.

20118 is an abundant number, since it is smaller than the sum of its proper divisors (25962).

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 (23040).

20118 is a wasteful number, since it uses less digits than its factorization.

20118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 491.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 20118 is about 141.8379356872. The cubic root of 20118 is about 27.1974550675.

Subtracting from 20118 its product of nonzero digits (16), we obtain a palindrome (20102).

The spelling of 20118 in words is "twenty thousand, one hundred eighteen".