18220 has 12 divisors (see below), whose sum is σ = 38304. Its totient is φ = 7280.

The previous prime is 18217. The next prime is 18223. The reversal of 18220 is 2281.

18220 = T₄₉ + T₅₀ + ... + T₆₀.

18220 is an esthetic number in base 8, because in such base its adjacent digits differ by 1.

It is an interprime number because it is at equal distance from previous prime (18217) and next prime (18223).

It is a nialpdrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 18220.

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

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 3 ways as a sum of consecutive naturals, for example, 436 + ... + 475.

It is an arithmetic number, because the mean of its divisors is an integer number (3192).

2¹⁸²²⁰ is an apocalyptic number.

18220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18220 is an abundant number, since it is smaller than the sum of its proper divisors (20084).

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 (19152).

18220 is a wasteful number, since it uses less digits than its factorization.

18220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 920 (or 918 counting only the distinct ones).

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

The square root of 18220 is about 134.9814802112. The cubic root of 18220 is about 26.3137528248.

It can be divided in two parts, 182 and 20, that added together give a palindrome (202).

The spelling of 18220 in words is "eighteen thousand, two hundred twenty".