Il numero romano CCCLXXXI nel sistema decimale vale: 381.
CCCLXXXI in latino si scrive trecenti octoginta unus,
mentre in italiano trecentottantuno.
CCCLXII, CCCLXIII, CCCLXIV, CCCLXV, CCCLXVI, CCCLXVII, CCCLXVIII, CCCLXIX, CCCLXX, CCCLXXI, CCCLXXII, CCCLXXIII, CCCLXXIV, CCCLXXV, CCCLXXVI, CCCLXXVII, CCCLXXVIII, CCCLXXIX, CCCLXXX, CCCLXXXII, CCCLXXXIII, CCCLXXXIV, CCCLXXXV, CCCLXXXVI, CCCLXXXVII, CCCLXXXVIII, CCCLXXXIX, CCCXC, CCCXCI, CCCXCII, CCCXCIII, CCCXCIV, CCCXCV, CCCXCVI, CCCXCVII, CCCXCVIII, CCCXCIX, CD