Il numero romano MDLXI nel sistema decimale vale: 1561.
MDLXI in latino si scrive mille quingenti sexaginta unus,
mentre in italiano millecinquecentosessantuno.
MDXLII, MDXLIII, MDXLIV, MDXLV, MDXLVI, MDXLVII, MDXLVIII, MDXLIX, MDL, MDLI, MDLII, MDLIII, MDLIV, MDLV, MDLVI, MDLVII, MDLVIII, MDLIX, MDLX, MDLXII, MDLXIII, MDLXIV, MDLXV, MDLXVI, MDLXVII, MDLXVIII, MDLXIX, MDLXX, MDLXXI, MDLXXII, MDLXXIII, MDLXXIV, MDLXXV, MDLXXVI, MDLXXVII, MDLXXVIII, MDLXXIX, MDLXXX