Question: 45 is prime or composite?
Answer: A composite number is a number that can be divided evenly by more numbers than 1 and itself. It is the opposite of a prime number. The number 45 can be evenly divided by 1, 3, 5, 9, 15 and 45, with no remainder. Since 45 cannot be divided by just 1 and 45, it is a composite number.