Il numero romano MDCCCLXI nel sistema decimale vale: 1861.
MDCCCLXI in latino si scrive mille octingenti sexaginta unus,
mentre in italiano milleottocentosessantuno.
MDCCCXLII, MDCCCXLIII, MDCCCXLIV, MDCCCXLV, MDCCCXLVI, MDCCCXLVII, MDCCCXLVIII, MDCCCXLIX, MDCCCL, MDCCCLI, MDCCCLII, MDCCCLIII, MDCCCLIV, MDCCCLV, MDCCCLVI, MDCCCLVII, MDCCCLVIII, MDCCCLIX, MDCCCLX, MDCCCLXII, MDCCCLXIII, MDCCCLXIV, MDCCCLXV, MDCCCLXVI, MDCCCLXVII, MDCCCLXVIII, MDCCCLXIX, MDCCCLXX, MDCCCLXXI, MDCCCLXXII, MDCCCLXXIII, MDCCCLXXIV, MDCCCLXXV, MDCCCLXXVI, MDCCCLXXVII, MDCCCLXXVIII, MDCCCLXXIX, MDCCCLXXX