Il numero romano MCLXXX nel sistema decimale vale: 1180.
MCLXXX in latino si scrive mille centum octoginta,
mentre in italiano millecentottanta.
MCLXI, MCLXII, MCLXIII, MCLXIV, MCLXV, MCLXVI, MCLXVII, MCLXVIII, MCLXIX, MCLXX, MCLXXI, MCLXXII, MCLXXIII, MCLXXIV, MCLXXV, MCLXXVI, MCLXXVII, MCLXXVIII, MCLXXIX, MCLXXXI, MCLXXXII, MCLXXXIII, MCLXXXIV, MCLXXXV, MCLXXXVI, MCLXXXVII, MCLXXXVIII, MCLXXXIX, MCXC, MCXCI, MCXCII, MCXCIII, MCXCIV, MCXCV, MCXCVI, MCXCVII, MCXCVIII, MCXCIX