18224 has 20 divisors (see below), whose sum is σ = 37944. Its totient is φ = 8448.

The previous prime is 18223. The next prime is 18229. The reversal of 18224 is 42281.

It is a Cunningham number, because it is equal to 135²-1.

It is a super-2 number, since 2×18224² = 664228352, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a nude number because it is divisible by every one of its digits.

It is a plaindrome in base 9 and base 15.

It is a zygodrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (18223) 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, 239 + ... + 305.

2¹⁸²²⁴ 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 18224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18972).

18224 is an abundant number, since it is smaller than the sum of its proper divisors (19720).

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

18224 is a wasteful number, since it uses less digits than its factorization.

18224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92 (or 86 counting only the distinct ones).

The product of its digits is 128, while the sum is 17.

The square root of 18224 is about 134.9962962455. The cubic root of 18224 is about 26.3156783153.

It can be divided in two parts, 18 and 224, that added together give a palindrome (242).

The spelling of 18224 in words is "eighteen thousand, two hundred twenty-four".