Is 9 a prime number and a factor of 18?

No, 9 is not a Prime number because it has factors other than 1 and itself. In this case, 9 is a factor of 18 because 9 multiplied by 2 equals 18. Prime numbers are numbers that have exactly two factors, 1 and the number itself, while factors are numbers that can be multiplied together to get the original number.