900
3, 6, 9
Of the ten digits, 0 is the only one that is divisible by 9.
972.
The least three-digit number that is divisible by both 5 and 9 is 135.
All you need to do is multiply the three numbers together:5 * 6 = 3030 * 9 = 270
987
6 + 4 + 6 = 16 1 + 6 = 7 → No; 646 is not divisible by 9 (there is a remainder of 7). ----------------------------------------- Only if the sum of the digits is divisible by 9 is the original number divisible by 9. Repeat the test on the sum until a single digit remains; only if this single digit is 9 is the original number divisible by 9, otherwise this single digit is the remainder when the original number is divided by 9.
144 is divisible by 12 and 9.
0, 3, 6 or 9.
999
225
180