18120 has 32 divisors (see below), whose sum is σ = 54720. Its totient is φ = 4800.

The previous prime is 18119. The next prime is 18121. The reversal of 18120 is 2181.

Added to its reverse (2181) it gives a triangular number (20301 = T₂₀₁).

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18119) and next prime (18121).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a nialpdrome in base 8.

It is a junction number, because it is equal to n+sod(n) for n = 18096 and 18105.

It is not an unprimeable number, because it can be changed into a prime (18121) 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, 45 + ... + 195.

It is an arithmetic number, because the mean of its divisors is an integer number (1710).

2¹⁸¹²⁰ is an apocalyptic number.

18120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27360).

18120 is an abundant number, since it is smaller than the sum of its proper divisors (36600).

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

18120 is a wasteful number, since it uses less digits than its factorization.

18120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165 (or 161 counting only the distinct ones).

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

The square root of 18120 is about 134.6105493637. The cubic root of 18120 is about 26.2655236976.

Adding to 18120 its reverse (2181), we get a triangular number (20301 = T₂₀₁).

The spelling of 18120 in words is "eighteen thousand, one hundred twenty".