No, it is an even number and therefore can be at least divided by 2.
7919
Yes.
Two.
Nope - it can be divided by 3.
It doesn't have two factors.
3, 5, and 7.
11/12 cannot be simplified - because 11 is a primenumber.
It's already in its simplest form - 67 is a primenumber.
18/29 cannot be simplified - because 29 is a primenumber !
I could bore you with a long mathematical explanation (ask if you want one), but to simplify things, 2 is a prime number.
It's already in its simplest form - since 43 is a primenumber.
The GCF of 17 & 52 is... 1 ! 17 is a primenumber - it's only factors are 1 & 17. 52 is an even number, who's factors are 1,2,4,13,26 & 52.