18540 has 36 divisors (see below), whose sum is σ = 56784. Its totient is φ = 4896.

The previous prime is 18539. The next prime is 18541. The reversal of 18540 is 4581.

It is an interprime number because it is at equal distance from previous prime (18539) and next prime (18541).

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (18541) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 129 + ... + 231.

2¹⁸⁵⁴⁰ is an apocalyptic number.

18540 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 18540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28392).

18540 is an abundant number, since it is smaller than the sum of its proper divisors (38244).

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

18540 is a wasteful number, since it uses less digits than its factorization.

18540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118 (or 113 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 18540 is about 136.1616686149. The cubic root of 18540 is about 26.4669101643.

It can be divided in two parts, 185 and 40, that added together give a square (225 = 15²).

The spelling of 18540 in words is "eighteen thousand, five hundred forty".