Il numero romano MCCCXCIX nel sistema decimale vale: 1399.
MCCCXCIX in latino si scrive mille trecenti nonaginta novem,
mentre in italiano milletrecentonovantanove.
MCCCLXXX, MCCCLXXXI, MCCCLXXXII, MCCCLXXXIII, MCCCLXXXIV, MCCCLXXXV, MCCCLXXXVI, MCCCLXXXVII, MCCCLXXXVIII, MCCCLXXXIX, MCCCXC, MCCCXCI, MCCCXCII, MCCCXCIII, MCCCXCIV, MCCCXCV, MCCCXCVI, MCCCXCVII, MCCCXCVIII, MCD, MCDI, MCDII, MCDIII, MCDIV, MCDV, MCDVI, MCDVII, MCDVIII, MCDIX, MCDX, MCDXI, MCDXII, MCDXIII, MCDXIV, MCDXV, MCDXVI, MCDXVII, MCDXVIII