18900 has 72 divisors (see below), whose sum is σ = 69440. Its totient is φ = 4320.
The previous prime is 18899. The next prime is 18911. The reversal of 18900 is 981.
Added to its reverse (981) it gives a square (19881 = 1412).
It is a Harshad number since it is a multiple of its sum of digits (18).
It is a zygodrome in base 6.
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 23 ways as a sum of consecutive naturals, for example, 2697 + ... + 2703.
218900 is an apocalyptic number.
18900 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 18900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34720).
18900 is an abundant number, since it is smaller than the sum of its proper divisors (50540).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
18900 is a wasteful number, since it uses less digits than its factorization.
18900 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 30 (or 17 counting only the distinct ones).
The product of its (nonzero) digits is 72, while the sum is 18.
The square root of 18900 is about 137.4772708487. The cubic root of 18900 is about 26.6371200523.
Adding to 18900 its reverse (981), we get a square (19881 = 1412).
The spelling of 18900 in words is "eighteen thousand, nine hundred".
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