18228 has 36 divisors (see below), whose sum is σ = 51072. Its totient is φ = 5040.

The previous prime is 18223. The next prime is 18229. The reversal of 18228 is 82281.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18223) by changing a digit.

18228 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 (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 573 + ... + 603.

2¹⁸²²⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25536).

18228 is an abundant number, since it is smaller than the sum of its proper divisors (32844).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18228 is a wasteful number, since it uses less digits than its factorization.

18228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52 (or 43 counting only the distinct ones).

The product of its digits is 256, while the sum is 21.

The square root of 18228 is about 135.0111106539. The cubic root of 18228 is about 26.3176035241.

18228 divided by its sum of digits (21) gives a palindrome (868).

It can be divided in two parts, 1822 and 8, that added together give a triangular number (1830 = T₆₀).

The spelling of 18228 in words is "eighteen thousand, two hundred twenty-eight".