Yes
No
No.
31, 37
No. It is divisible by 7. 7*7 = 49
A prime number is a number that can not be divisible by any other number besides one.
3 x 3 x 7 = 63
No, 98 is divisible by 2; therefore, it is a composite number.
81 is a composite number because its factors are more than 2
Siebzehn
24
XVII