Il numero romano MCDXXIII nel sistema decimale vale: 1423.
MCDXXIII in latino si scrive mille quadringenti viginti tres,
mentre in italiano millequattrocentoventitré.
MCDIV, MCDV, MCDVI, MCDVII, MCDVIII, MCDIX, MCDX, MCDXI, MCDXII, MCDXIII, MCDXIV, MCDXV, MCDXVI, MCDXVII, MCDXVIII, MCDXIX, MCDXX, MCDXXI, MCDXXII, MCDXXIV, MCDXXV, MCDXXVI, MCDXXVII, MCDXXVIII, MCDXXIX, MCDXXX, MCDXXXI, MCDXXXII, MCDXXXIII, MCDXXXIV, MCDXXXV, MCDXXXVI, MCDXXXVII, MCDXXXVIII, MCDXXXIX, MCDXL, MCDXLI, MCDXLII