We can see easily this is an even number, so let's first divide by 2.
432=2*216
We can see the remaining 216 is still even so we continue.
432=2*2*108
And continue
432=2*2*2*54
and continue
432=2*2*2*2*27
Now we can see that 27 is a multiple of 3 in fact its 3^3.
So we can conclude that 432=
