18500 has 24 divisors (see below), whose sum is σ = 41496. Its totient is φ = 7200.

The previous prime is 18493. The next prime is 18503. The reversal of 18500 is 581.

It can be written as a sum of positive squares in 4 ways, for example, as 4 + 18496 = 2^2 + 136^2 .

It is a plaindrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (18503) 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, 482 + ... + 518.

It is an arithmetic number, because the mean of its divisors is an integer number (1729).

2¹⁸⁵⁰⁰ is an apocalyptic number.

18500 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 18500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20748).

18500 is an abundant number, since it is smaller than the sum of its proper divisors (22996).

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

18500 is a wasteful number, since it uses less digits than its factorization.

18500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56 (or 44 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 18500 is about 136.0147050874. The cubic root of 18500 is about 26.4478623635.

The spelling of 18500 in words is "eighteen thousand, five hundred".