Il numero romano MMDCCLXXX nel sistema decimale vale: 2780.
MMDCCLXXX in latino si scrive duo milia septingenti octoginta,
mentre in italiano duemilasettecentottanta.
MMDCCLXI, MMDCCLXII, MMDCCLXIII, MMDCCLXIV, MMDCCLXV, MMDCCLXVI, MMDCCLXVII, MMDCCLXVIII, MMDCCLXIX, MMDCCLXX, MMDCCLXXI, MMDCCLXXII, MMDCCLXXIII, MMDCCLXXIV, MMDCCLXXV, MMDCCLXXVI, MMDCCLXXVII, MMDCCLXXVIII, MMDCCLXXIX, MMDCCLXXXI, MMDCCLXXXII, MMDCCLXXXIII, MMDCCLXXXIV, MMDCCLXXXV, MMDCCLXXXVI, MMDCCLXXXVII, MMDCCLXXXVIII, MMDCCLXXXIX, MMDCCXC, MMDCCXCI, MMDCCXCII, MMDCCXCIII, MMDCCXCIV, MMDCCXCV, MMDCCXCVI, MMDCCXCVII, MMDCCXCVIII, MMDCCXCIX