Abstract. In [3] and [2], Atanassov introduced the two arithmetic functionscalled the irrational factor and the restrictive factor, respectively. Alkan, Ledoan, Panaitopol, and the authors explore properties of these arithmetic functions in [1], [7], [8] and [9]. In the present paper, we generalize these functions to a larger class of elements of PSL 2 (Z), and explore some of the properties of these maps.