My dataset consists of a numeric variable (called "N4") and several categorical variables that affect the numeric variable. For example there is a categorical variable called "die" that if it equals "alpha" then N4 takes values around 100, if it equals "beta" then N4 takes values around 300.

My goal is to figure out which of the categorical variables most affects my numeric variable.

Can it make sense to turn categorical variables into numerical variables and calculate correlation? Is there any other more effective analysis?