18100 has 18 divisors (see below), whose sum is σ = 39494. Its totient is φ = 7200.

The previous prime is 18097. The next prime is 18119. The reversal of 18100 is 181.

It can be written as a sum of positive squares in 3 ways, for example, as 144 + 17956 = 12^2 + 134^2 .

It is a super-2 number, since 2×18100² = 655220000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a plaindrome in base 15.

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 10 + ... + 190.

2¹⁸¹⁰⁰ is an apocalyptic number.

18100 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 18100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19747).

18100 is an abundant number, since it is smaller than the sum of its proper divisors (21394).

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

18100 is a wasteful number, since it uses less digits than its factorization.

18100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195 (or 188 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 18100 is about 134.5362404707. The cubic root of 18100 is about 26.2558565920.

Adding to 18100 its reverse (181), we get a palindrome (18281).

Multiplying 18100 by its reverse (181), we get a square (3276100 = 1810²).

18100 divided by its reverse (181) gives a square (100 = 10²).

The spelling of 18100 in words is "eighteen thousand, one hundred".