13 is already prime. It doesn't need a rainbow.
A factor rainbow for 13 would look like this: 13 = 1 x 13.
12
65 / \ 13 5
26 / \ 2 13
13 is already prime. It doesn't need a tree.
3 * 13 (both prime numbers)
Multiples of 13, like 13, 26 and 39.
52 / \ 26 2 / \ 13 2 Kind of like that I think. Just get down to prime numbers
Multiples of 13 like 13, 26, 39 and so on.
It can be. 13 is a factor of 26.
I don't know where it is found. (in fact that is what i was searching for) but i can say what it looks like. Mystic quartz looks like an exploding rainbow (with a kaleidoscope effect) when light is refracted off of it correctly. (Answered by a 13 year old:))
13 is not a factor of 126.