It is a harmonic number, since the harmonic mean of its divisors is an integer.
It is an Ulam number.
It is a plaindrome in base 16.
It is a congruent number.
It is an unprimeable number.
218620 is an apocalyptic number.
18620 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 18620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23940).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
18620 is a wasteful number, since it uses less digits than its factorization.
18620 is an odious number, because the sum of its binary digits is odd.
The square root of 18620 is about 136.4551208273. The cubic root of 18620 is about 26.5049237321.
The spelling of 18620 in words is "eighteen thousand, six hundred twenty".