Subtracting from 19900 its sum of digits (19), we obtain a square (19881 = 1412).
It is a congruent number.
It is an unprimeable number.
219900 is an apocalyptic number.
19900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.
19900 is the 67-th centered nonagonal number.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 19900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21700).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
19900 is a wasteful number, since it uses less digits than its factorization.
19900 is an odious number, because the sum of its binary digits is odd.
The square root of 19900 is about 141.0673597967. The cubic root of 19900 is about 27.0988602617.
The spelling of 19900 in words is "nineteen thousand, nine hundred".