Il numero romano MDCCCXL nel sistema decimale vale: 1840.
MDCCCXL in latino si scrive mille octingenti quadraginta,
mentre in italiano milleottocentoquaranta.
MDCCCXXI, MDCCCXXII, MDCCCXXIII, MDCCCXXIV, MDCCCXXV, MDCCCXXVI, MDCCCXXVII, MDCCCXXVIII, MDCCCXXIX, MDCCCXXX, MDCCCXXXI, MDCCCXXXII, MDCCCXXXIII, MDCCCXXXIV, MDCCCXXXV, MDCCCXXXVI, MDCCCXXXVII, MDCCCXXXVIII, MDCCCXXXIX, MDCCCXLI, MDCCCXLII, MDCCCXLIII, MDCCCXLIV, MDCCCXLV, MDCCCXLVI, MDCCCXLVII, MDCCCXLVIII, MDCCCXLIX, MDCCCL, MDCCCLI, MDCCCLII, MDCCCLIII, MDCCCLIV, MDCCCLV, MDCCCLVI, MDCCCLVII, MDCCCLVIII, MDCCCLIX