Il numero romano MMDCCCI nel sistema decimale vale: 2801.
MMDCCCI in latino si scrive duo milia octingenti unus,
mentre in italiano duemilaottocentouno.
MMDCCLXXXII, MMDCCLXXXIII, MMDCCLXXXIV, MMDCCLXXXV, MMDCCLXXXVI, MMDCCLXXXVII, MMDCCLXXXVIII, MMDCCLXXXIX, MMDCCXC, MMDCCXCI, MMDCCXCII, MMDCCXCIII, MMDCCXCIV, MMDCCXCV, MMDCCXCVI, MMDCCXCVII, MMDCCXCVIII, MMDCCXCIX, MMDCCC, MMDCCCII, MMDCCCIII, MMDCCCIV, MMDCCCV, MMDCCCVI, MMDCCCVII, MMDCCCVIII, MMDCCCIX, MMDCCCX, MMDCCCXI, MMDCCCXII, MMDCCCXIII, MMDCCCXIV, MMDCCCXV, MMDCCCXVI, MMDCCCXVII, MMDCCCXVIII, MMDCCCXIX, MMDCCCXX