Il numero romano MMDXCIX nel sistema decimale vale: 2599.
MMDXCIX in latino si scrive duo milia quingenti nonaginta novem,
mentre in italiano duemilacinquecentonovantanove.
MMDLXXX, MMDLXXXI, MMDLXXXII, MMDLXXXIII, MMDLXXXIV, MMDLXXXV, MMDLXXXVI, MMDLXXXVII, MMDLXXXVIII, MMDLXXXIX, MMDXC, MMDXCI, MMDXCII, MMDXCIII, MMDXCIV, MMDXCV, MMDXCVI, MMDXCVII, MMDXCVIII, MMDC, MMDCI, MMDCII, MMDCIII, MMDCIV, MMDCV, MMDCVI, MMDCVII, MMDCVIII, MMDCIX, MMDCX, MMDCXI, MMDCXII, MMDCXIII, MMDCXIV, MMDCXV, MMDCXVI, MMDCXVII, MMDCXVIII