According to the Remainder Theorem, if a polynomial \( f(x) \) evaluates to zero at a certain point, say \( f(a) = 0 \), then \( x - a \) is a factor of \( f(x) \).
Since it is given that \( f(12) = 0 \), we can conclude that \( x - 12 \) is a factor of \( f(x) \).
So, the answer is that \( x - 12 \) is a factor of \( f(x) \).