Il numero romano MDLXXXI nel sistema decimale vale: 1581.
MDLXXXI in latino si scrive mille quingenti octoginta unus,
mentre in italiano millecinquecentottantuno.
MDLXII, MDLXIII, MDLXIV, MDLXV, MDLXVI, MDLXVII, MDLXVIII, MDLXIX, MDLXX, MDLXXI, MDLXXII, MDLXXIII, MDLXXIV, MDLXXV, MDLXXVI, MDLXXVII, MDLXXVIII, MDLXXIX, MDLXXX, MDLXXXII, MDLXXXIII, MDLXXXIV, MDLXXXV, MDLXXXVI, MDLXXXVII, MDLXXXVIII, MDLXXXIX, MDXC, MDXCI, MDXCII, MDXCIII, MDXCIV, MDXCV, MDXCVI, MDXCVII, MDXCVIII, MDXCIX, MDC