The number divided by the sum of it's digits always = 37
111, 1+1+1 = 3 , 111/3 = 37
222, 2+2+2 = 6 , 222/6 = 37
333, 3+3+3 = 9 , 333/9 = 37
444, 4+4+4 = 12, 444/12 = 37
555, 5+5+5 = 15, 555/15 = 37
666, 6+6+6 = 18, 666/18 = 37
777, 7+7+7 = 21, 777/21 = 37
888, 8+8+8 = 24, 888/24 = 37
999, 9+9+9 = 27, 999/27 = 37
9 x 37 = 333