Il numero romano MMCLXI nel sistema decimale vale: 2161.
MMCLXI in latino si scrive duo milia centum sexaginta unus,
mentre in italiano duemilacentosessantuno.
MMCXLII, MMCXLIII, MMCXLIV, MMCXLV, MMCXLVI, MMCXLVII, MMCXLVIII, MMCXLIX, MMCL, MMCLI, MMCLII, MMCLIII, MMCLIV, MMCLV, MMCLVI, MMCLVII, MMCLVIII, MMCLIX, MMCLX, MMCLXII, MMCLXIII, MMCLXIV, MMCLXV, MMCLXVI, MMCLXVII, MMCLXVIII, MMCLXIX, MMCLXX, MMCLXXI, MMCLXXII, MMCLXXIII, MMCLXXIV, MMCLXXV, MMCLXXVI, MMCLXXVII, MMCLXXVIII, MMCLXXIX, MMCLXXX