If this number is well examined there are six 9s, four 6s, six 3s... If add up these numbers together it'll always give a multiple of three because the numbers itself(9,6,3)are multiple of 3. So the numbers you need to add are 8,2(twice) ,1 and 5..... 8+2+2+1+5=18... Hence the number is divisible by 3........
