Adding to 20340 its reverse (4302), we get a palindrome (24642).
It is a tau number, because it is divible by the number of its divisors (36).
20340 is an undulating number in base 15.
It is a nialpdrome in base 12.
It is a congruent number.
20340 is an untouchable number, because it is not equal to the sum of proper divisors of any number.
220340 is an apocalyptic number.
20340 is a gapful number since it is divisible by the number (20) 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 20340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31122).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
20340 is a wasteful number, since it uses less digits than its factorization.
20340 is an odious number, because the sum of its binary digits is odd.
The square root of 20340 is about 142.6183718881. The cubic root of 20340 is about 27.2971296745.
The spelling of 20340 in words is "twenty thousand, three hundred forty", and thus it is an iban number.