1 1/2 one and a half
The number is 0.3
3 is a prime number because it has exactly two factors which are whole numbers: itself and one. This is the definition of a prime.
The square of a prime number.
A number has exactly three factors if and only if it is the square of a prime number.
no there are 4
4 9 25 49
1617 is not a prime number. The sum of its digits is a multiple of 3, so 3 is one of its factors. A prime number has exactly two factors, 1 and the number itself, so 1617 is a composite number.
Yes it is. If the digits of a number added together will divide exactly by three (or nine) then the number itself will also divide exactly by 3 or 9. In this case, 1+8+9=18... which is exactly divisible by 3.