[" i) Find all the numbers having exactly one lactor."],[" i) Find numbers between "1" and "100" having exactly three factors."]

(i) Is there any counting number having no factor at all ? (ii) Find all the numbers having exactly one factor. (iii) Find numbers between 1 and 100 having exactly three factors.

Which are the numbers between 1 and 100 having exactly three factors?

Find two numbers with exactly five factors.

How many numbers between 100 and 1000 have the digit 7 exactly once?

How many numbers between 100 and 500 are exactly divisible by 7 ?

What is the smallest number with exactly five factors?