It is a congruent number.
It is an unprimeable number.
218240 is an apocalyptic number.
18240 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 18240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30480).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
18240 is a wasteful number, since it uses less digits than its factorization.
18240 is an odious number, because the sum of its binary digits is odd.
The square root of 18240 is about 135.0555441291. The cubic root of 18240 is about 26.3233774610.
Subtracting from 18240 its sum of digits (15), we obtain a square (18225 = 1352).
The spelling of 18240 in words is "eighteen thousand, two hundred forty".