Il numero romano MMMCDXX nel sistema decimale vale: 3420.
MMMCDXX in latino si scrive tria milia quadringenti viginti,
mentre in italiano tremilaquattrocentoventi.
MMMCDI, MMMCDII, MMMCDIII, MMMCDIV, MMMCDV, MMMCDVI, MMMCDVII, MMMCDVIII, MMMCDIX, MMMCDX, MMMCDXI, MMMCDXII, MMMCDXIII, MMMCDXIV, MMMCDXV, MMMCDXVI, MMMCDXVII, MMMCDXVIII, MMMCDXIX, MMMCDXXI, MMMCDXXII, MMMCDXXIII, MMMCDXXIV, MMMCDXXV, MMMCDXXVI, MMMCDXXVII, MMMCDXXVIII, MMMCDXXIX, MMMCDXXX, MMMCDXXXI, MMMCDXXXII, MMMCDXXXIII, MMMCDXXXIV, MMMCDXXXV, MMMCDXXXVI, MMMCDXXXVII, MMMCDXXXVIII, MMMCDXXXIX