Il numero romano MMMMDCXCI nel sistema decimale vale: 4691.
MMMMDCXCI in latino si scrive quattuor milia sescenti nonaginta unus,
mentre in italiano quattromilaseicentonovantuno.
MMMMDCLXXII, MMMMDCLXXIII, MMMMDCLXXIV, MMMMDCLXXV, MMMMDCLXXVI, MMMMDCLXXVII, MMMMDCLXXVIII, MMMMDCLXXIX, MMMMDCLXXX, MMMMDCLXXXI, MMMMDCLXXXII, MMMMDCLXXXIII, MMMMDCLXXXIV, MMMMDCLXXXV, MMMMDCLXXXVI, MMMMDCLXXXVII, MMMMDCLXXXVIII, MMMMDCLXXXIX, MMMMDCXC, MMMMDCXCII, MMMMDCXCIII, MMMMDCXCIV, MMMMDCXCV, MMMMDCXCVI, MMMMDCXCVII, MMMMDCXCVIII, MMMMDCXCIX, MMMMDCC, MMMMDCCI, MMMMDCCII, MMMMDCCIII, MMMMDCCIV, MMMMDCCV, MMMMDCCVI, MMMMDCCVII, MMMMDCCVIII, MMMMDCCIX, MMMMDCCX