Il numero romano MMMMDCXXIII nel sistema decimale vale: 4623.
MMMMDCXXIII in latino si scrive quattuor milia sescenti viginti tres,
mentre in italiano quattromilaseicentoventitré.
MMMMDCIV, MMMMDCV, MMMMDCVI, MMMMDCVII, MMMMDCVIII, MMMMDCIX, MMMMDCX, MMMMDCXI, MMMMDCXII, MMMMDCXIII, MMMMDCXIV, MMMMDCXV, MMMMDCXVI, MMMMDCXVII, MMMMDCXVIII, MMMMDCXIX, MMMMDCXX, MMMMDCXXI, MMMMDCXXII, MMMMDCXXIV, MMMMDCXXV, MMMMDCXXVI, MMMMDCXXVII, MMMMDCXXVIII, MMMMDCXXIX, MMMMDCXXX, MMMMDCXXXI, MMMMDCXXXII, MMMMDCXXXIII, MMMMDCXXXIV, MMMMDCXXXV, MMMMDCXXXVI, MMMMDCXXXVII, MMMMDCXXXVIII, MMMMDCXXXIX, MMMMDCXL, MMMMDCXLI, MMMMDCXLII