Which of these numbers is $6$6 a factor of?

$30$30

$32$32

$17$17

$39$39

If we multiply $4$4 by $14$14, we get $56$56, so $4$4 and $14$14 make a factor pair of $56$56.

What is the highest common factor of $24$24 and $36$36?

Is $\left(8,2\right)$(8,2) a factor pair of $8$8?