Il numero romano MDXCIX nel sistema decimale vale: 1599.
MDXCIX in latino si scrive mille quingenti nonaginta novem,
mentre in italiano millecinquecentonovantanove.
MDLXXX, MDLXXXI, MDLXXXII, MDLXXXIII, MDLXXXIV, MDLXXXV, MDLXXXVI, MDLXXXVII, MDLXXXVIII, MDLXXXIX, MDXC, MDXCI, MDXCII, MDXCIII, MDXCIV, MDXCV, MDXCVI, MDXCVII, MDXCVIII, MDC, MDCI, MDCII, MDCIII, MDCIV, MDCV, MDCVI, MDCVII, MDCVIII, MDCIX, MDCX, MDCXI, MDCXII, MDCXIII, MDCXIV, MDCXV, MDCXVI, MDCXVII, MDCXVIII