2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/122786We provide an exact formula for the complex exponents in the modular product expansion of the modular units, and deduce a characterization of the modular units in terms of the growth of these exponents, answering a question of W. Kohnen.Number Theory11F03; 11F11A characterization of the modular unitstext