Il numero romano MMCDXXXI nel sistema decimale vale: 2431.
MMCDXXXI in latino si scrive duo milia quadringenti triginta unus,
mentre in italiano duemilaquattrocentotrentuno.
MMCDXII, MMCDXIII, MMCDXIV, MMCDXV, MMCDXVI, MMCDXVII, MMCDXVIII, MMCDXIX, MMCDXX, MMCDXXI, MMCDXXII, MMCDXXIII, MMCDXXIV, MMCDXXV, MMCDXXVI, MMCDXXVII, MMCDXXVIII, MMCDXXIX, MMCDXXX, MMCDXXXII, MMCDXXXIII, MMCDXXXIV, MMCDXXXV, MMCDXXXVI, MMCDXXXVII, MMCDXXXVIII, MMCDXXXIX, MMCDXL, MMCDXLI, MMCDXLII, MMCDXLIII, MMCDXLIV, MMCDXLV, MMCDXLVI, MMCDXLVII, MMCDXLVIII, MMCDXLIX, MMCDL