Il numero romano MMMMLXXX nel sistema decimale vale: 4080.
MMMMLXXX in latino si scrive quattuor milia octoginta,
mentre in italiano quattromilaottanta.
MMMMLXI, MMMMLXII, MMMMLXIII, MMMMLXIV, MMMMLXV, MMMMLXVI, MMMMLXVII, MMMMLXVIII, MMMMLXIX, MMMMLXX, MMMMLXXI, MMMMLXXII, MMMMLXXIII, MMMMLXXIV, MMMMLXXV, MMMMLXXVI, MMMMLXXVII, MMMMLXXVIII, MMMMLXXIX, MMMMLXXXI, MMMMLXXXII, MMMMLXXXIII, MMMMLXXXIV, MMMMLXXXV, MMMMLXXXVI, MMMMLXXXVII, MMMMLXXXVIII, MMMMLXXXIX, MMMMXC, MMMMXCI, MMMMXCII, MMMMXCIII, MMMMXCIV, MMMMXCV, MMMMXCVI, MMMMXCVII, MMMMXCVIII, MMMMXCIX