It is a happy number.
It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1211 = 7 ⋅173.
It is a cyclic number.
It is a Duffinian number.
It is a Curzon number.
It is an amenable number.
1121 is an equidigital number, since it uses as much as digits as its factorization.
1121 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 78.
The square root of 1121 is about 33.4813380856. The cubic root of 1121 is about 10.3880780546.
Adding to 1121 its reverse (1211), we get a palindrome (2332).
Multiplying 1121 by its reverse (1211), we get a palindrome (1357531).
The spelling of 1121 in words is "one thousand, one hundred twenty-one", and thus it is an iban number.