No, 111 is not a prime number.
A prime number is defined as a natural number greater than 1 that has no positive divisors other than 1 and itself. In simpler terms, a prime number can only be divided evenly (without a remainder) by 1 and the number itself.
In the case of 111, it can be divided evenly by 1, 3, 37, and 111. Since it has divisors other than 1 and 111, specifically 3 and 37, it does not meet the criteria to be a prime number. Therefore, we conclude that 111 is a composite number.