22018 has 8 divisors (see below), whose sum is σ = 33660. Its totient is φ = 10800.

The previous prime is 22013. The next prime is 22027. The reversal of 22018 is 81022.

It can be written as a sum of positive squares in 2 ways, for example, as 18769 + 3249 = 137^2 + 57^2 .

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

It is a plaindrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 21989 and 22007.

It is not an unprimeable number, because it can be changed into a prime (22013) by changing a digit.

22018 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 148 + ... + 256.

2²²⁰¹⁸ is an apocalyptic number.

22018 is a deficient number, since it is larger than the sum of its proper divisors (11642).

22018 is a wasteful number, since it uses less digits than its factorization.

22018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 22018 is about 148.3846353232. The cubic root of 22018 is about 28.0280331488.

It can be divided in two parts, 2201 and 8, that added together give a square (2209 = 47²).

The spelling of 22018 in words is "twenty-two thousand, eighteen".