It isn't.
1331 is a composite number. It is equal to 11 x 11 x 11, or 113.
15 is a composite number. 11 is a prime number.
1573 is not prime. 1573 = 11 * 11 * 13. Thus, it is a composite number.
11 is prime.
11 is prime.
121 is a composite number. It is divisible by 1, 11, and 121.
11 is a prime and contains no composite numbers.
no its a prime number
45, 33 and 27 are composite numbers. 11 is a prime number.
The number 121 is a composite number, since it is divisible by 11.
51 is composite.
It is 11.