阶乘 Traditional form: 階乘 Pinyin (reading): jiēchéng Definitions: the factorial of a number, e.g. 5! = 5.4.3.2.1 = 120 Characters: 阶 - stairs, steps; degree, rank 乘 - ride, mount; to make use of; to ascend; to multiply Traditional characters: 階 - stairs, steps; degree, rank 乘 - ride, mount; to make use of; to ascend; to multiply