The number is 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 number is 0.3
The square of a prime number.
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.
Oh, dude, that's an easy one. 3 can go into 3 exactly one time. It's like trying to fit a square peg into a square hole - it just slides right in there. So, yeah, just once.
Prime squares
(3+(3x3))/3=4
One is.
12
Exactly as in the question: three = 3
333 3 11 111
The number 1.666666666 is almost exactly equal to one and two thirds (to be exactly equal, the decimal expansion continues to infinity) which as a fraction could be written as 5/3.