Subtracting from 1660 its reverse (661), we obtain a palindrome (999).
1660 is nontrivially palindromic in base 13 and base 14.
1660 is an esthetic number in base 13, because in such base its adjacent digits differ by 1.
It is an Ulam number.
1660 is an undulating number in base 13 and base 14.
It is a plaindrome in base 9, base 11 and base 16.
It is a nialpdrome in base 12.
It is a zygodrome in base 2 and base 9.
It is a self number, because there is not a number n which added to its sum of digits gives 1660.
It is a congruent number.
1660 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 pseudoperfect number, because it is the sum of a subset of its proper divisors.
1660 is a wasteful number, since it uses less digits than its factorization.
1660 is an odious number, because the sum of its binary digits is odd.
The square root of 1660 is about 40.7430975749. The cubic root of 1660 is about 11.8404814754.
The spelling of 1660 in words is "one thousand, six hundred sixty".