Il numero romano MMMDCCXCI nel sistema decimale vale: 3791.
MMMDCCXCI in latino si scrive tria milia septingenti nonaginta unus,
mentre in italiano tremilasettecentonovantuno.
MMMDCCLXXII, MMMDCCLXXIII, MMMDCCLXXIV, MMMDCCLXXV, MMMDCCLXXVI, MMMDCCLXXVII, MMMDCCLXXVIII, MMMDCCLXXIX, MMMDCCLXXX, MMMDCCLXXXI, MMMDCCLXXXII, MMMDCCLXXXIII, MMMDCCLXXXIV, MMMDCCLXXXV, MMMDCCLXXXVI, MMMDCCLXXXVII, MMMDCCLXXXVIII, MMMDCCLXXXIX, MMMDCCXC, MMMDCCXCII, MMMDCCXCIII, MMMDCCXCIV, MMMDCCXCV, MMMDCCXCVI, MMMDCCXCVII, MMMDCCXCVIII, MMMDCCXCIX, MMMDCCC, MMMDCCCI, MMMDCCCII, MMMDCCCIII, MMMDCCCIV, MMMDCCCV, MMMDCCCVI, MMMDCCCVII, MMMDCCCVIII, MMMDCCCIX, MMMDCCCX