Il numero romano MDCCCXII nel sistema decimale vale: 1812.
MDCCCXII in latino si scrive mille octingenti duodecim,
mentre in italiano milleottocentododici.
MDCCXCIII, MDCCXCIV, MDCCXCV, MDCCXCVI, MDCCXCVII, MDCCXCVIII, MDCCXCIX, MDCCC, MDCCCI, MDCCCII, MDCCCIII, MDCCCIV, MDCCCV, MDCCCVI, MDCCCVII, MDCCCVIII, MDCCCIX, MDCCCX, MDCCCXI, MDCCCXIII, MDCCCXIV, MDCCCXV, MDCCCXVI, MDCCCXVII, MDCCCXVIII, MDCCCXIX, MDCCCXX, MDCCCXXI, MDCCCXXII, MDCCCXXIII, MDCCCXXIV, MDCCCXXV, MDCCCXXVI, MDCCCXXVII, MDCCCXXVIII, MDCCCXXIX, MDCCCXXX, MDCCCXXXI