Il numero romano CCCLXVI nel sistema decimale vale: 366.
CCCLXVI in latino si scrive trecenti sexaginta sex,
mentre in italiano trecentosessantasei.
CCCXLVII, CCCXLVIII, CCCXLIX, CCCL, CCCLI, CCCLII, CCCLIII, CCCLIV, CCCLV, CCCLVI, CCCLVII, CCCLVIII, CCCLIX, CCCLX, CCCLXI, CCCLXII, CCCLXIII, CCCLXIV, CCCLXV, CCCLXVII, CCCLXVIII, CCCLXIX, CCCLXX, CCCLXXI, CCCLXXII, CCCLXXIII, CCCLXXIV, CCCLXXV, CCCLXXVI, CCCLXXVII, CCCLXXVIII, CCCLXXIX, CCCLXXX, CCCLXXXI, CCCLXXXII, CCCLXXXIII, CCCLXXXIV, CCCLXXXV