Adding to 20304 its reverse (40302), we get a palindrome (60606).
It is a nialpdrome in base 12.
It is a congruent number.
It is an unprimeable number.
20304 is an untouchable number, because it is not equal to the sum of proper divisors of any number.
220304 is an apocalyptic number.
20304 is a gapful number since it is divisible by the number (24) 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 20304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29760).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
20304 is a wasteful number, since it uses less digits than its factorization.
20304 is an odious number, because the sum of its binary digits is odd.
The square root of 20304 is about 142.4921050445. The cubic root of 20304 is about 27.2810156627.
The spelling of 20304 in words is "twenty thousand, three hundred four", and thus it is an iban number.