It is a tau number, because it is divible by the number of its divisors (60).
It is a nialpdrome in base 3 and base 12.
It is a zygodrome in base 3.
It is a congruent number.
19440 is an untouchable number, because it is not equal to the sum of proper divisors of any number.
219440 is an apocalyptic number.
19440 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 19440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33852).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
19440 is an equidigital number, since it uses as much as digits as its factorization.
19440 is an evil number, because the sum of its binary digits is even.
The square root of 19440 is about 139.4274004635. The cubic root of 19440 is about 26.8884284793. Note that the first 3 decimals are identical.
The spelling of 19440 in words is "nineteen thousand, four hundred forty".