Il numero romano CDXL nel sistema decimale vale: 440.
CDXL in latino si scrive quadringenti quadraginta,
mentre in italiano quattrocentoquaranta.
CDXXI, CDXXII, CDXXIII, CDXXIV, CDXXV, CDXXVI, CDXXVII, CDXXVIII, CDXXIX, CDXXX, CDXXXI, CDXXXII, CDXXXIII, CDXXXIV, CDXXXV, CDXXXVI, CDXXXVII, CDXXXVIII, CDXXXIX, CDXLI, CDXLII, CDXLIII, CDXLIV, CDXLV, CDXLVI, CDXLVII, CDXLVIII, CDXLIX, CDL, CDLI, CDLII, CDLIII, CDLIV, CDLV, CDLVI, CDLVII, CDLVIII, CDLIX