A positive integer is called terrific if it has exactly $10$ positive divisors. What is the smallest terrific positive integer?
If a number is written in the form of pa1pb2pc3..., where all p's are prime numners, it will have (a+1)(b+1)(c+1)... factors. Therefore, a terrific number must be writen in the form of either p9, or p11p42. The smallest possibilities for each respectively are 2^9 or 512 and 3(2^4) or 48. Therefore, 48 is the smallest terrific number.