It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 36611 = 31 ⋅1181.
It is a cyclic number.
It is a Duffinian number.
It is a plaindrome in base 6, base 9 and base 12.
It is a nialpdrome in base 11.
It is a congruent number.
11663 is a Friedman number, since it can be written as 16*3^6-1, using all its digits and the basic arithmetic operations.
211663 is an apocalyptic number.
11663 is a wasteful number, since it uses less digits than its factorization.
11663 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 216.
The square root of 11663 is about 107.9953702711. The cubic root of 11663 is about 22.6779307720.
The spelling of 11663 in words is "eleven thousand, six hundred sixty-three".