Please help quick!! solve for side!

The general form of the quetion of a circle is ax^2+by^2+cx+dy+e=0 where a=b=0 if the circle has a radius of three units and the center lies on the y axis which set of values of a, b, c, d, and e might correspond to the circle

Ling listed all of the factors of a mystery number: 1,2,4,8,16,32 what is the mystery number?

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much