20720 is nontrivially palindromic in base 6.
It is a tau number, because it is divible by the number of its divisors (40).
It is a nialpdrome in base 12.
It is a zygodrome in base 4.
It is a congruent number.
It is an unprimeable number.
220720 is an apocalyptic number.
20720 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 20720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28272).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
20720 is a wasteful number, since it uses less digits than its factorization.
20720 is an evil number, because the sum of its binary digits is even.
The square root of 20720 is about 143.9444337236. The cubic root of 20720 is about 27.4660738658.
The spelling of 20720 in words is "twenty thousand, seven hundred twenty", and thus it is an iban number.