Il numero romano MMCDXXIII nel sistema decimale vale: 2423.
MMCDXXIII in latino si scrive duo milia quadringenti viginti tres,
mentre in italiano duemilaquattrocentoventitré.
MMCDIV, MMCDV, MMCDVI, MMCDVII, MMCDVIII, MMCDIX, MMCDX, MMCDXI, MMCDXII, MMCDXIII, MMCDXIV, MMCDXV, MMCDXVI, MMCDXVII, MMCDXVIII, MMCDXIX, MMCDXX, MMCDXXI, MMCDXXII, MMCDXXIV, MMCDXXV, MMCDXXVI, MMCDXXVII, MMCDXXVIII, MMCDXXIX, MMCDXXX, MMCDXXXI, MMCDXXXII, MMCDXXXIII, MMCDXXXIV, MMCDXXXV, MMCDXXXVI, MMCDXXXVII, MMCDXXXVIII, MMCDXXXIX, MMCDXL, MMCDXLI, MMCDXLII