1720 is nontrivially palindromic in base 7.
1720 is an esthetic number in base 9, because in such base its adjacent digits differ by 1.
It is a plaindrome in base 14 and base 15.
It is a nialpdrome in base 12.
It is a congruent number.
1720 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 1720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1980).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
1720 is a wasteful number, since it uses less digits than its factorization.
1720 is an evil number, because the sum of its binary digits is even.
The square root of 1720 is about 41.4728827067. The cubic root of 1720 is about 11.9814528298.
Adding to 1720 its reverse (271), we get a palindrome (1991).
The spelling of 1720 in words is "one thousand, seven hundred twenty", and thus it is an iban number.