This paper investigates possibilities of deriving new digital-to-analog converter (DAC) architectures based on polygonal and prime number theories. As the result, configurations of polygonal number DACs and prime number DACs are obtained; each consists of a few current sources, a resistor network, switch arrays and a decoder circuit. Whole circuits are designed and their operations are confirmed with simulation; they work as DAC in principle. In many cases, analog/mixed-signal circuit architecture design relies on intuitions and experiences of the designer, but here we demonstrate that it is feasible to derive different DAC architectures from conventional ones based on mathematical theory.