4020 is an esthetic number in base 9, because in such base its adjacent digits differ by 1.
It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.
It is a nialpdrome in base 8 and base 16.
It is a congruent number.
24020 is an apocalyptic number.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 4020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5712).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
4020 is a wasteful number, since it uses less digits than its factorization.
4020 is an evil number, because the sum of its binary digits is even.
The square root of 4020 is about 63.4034699366. The cubic root of 4020 is about 15.9004232315.
Adding to 4020 its reverse (204), we get a palindrome (4224).
The spelling of 4020 in words is "four thousand, twenty", and thus it is an iban number.