3, 7, 9, 13, 21, 39, 63, 91, 117, 273.
Yes.
No. 6 is smaller than 57819 so it cannot be divisible by it.
One easy way to check is sum of digits. 819: 8+1+9 = 18. 18 is a multiple of 3. 819 is divisible by 3. 440: 4+4+0 = 8. Not a multiple of 3. 440 is not divisible by 3. 222: 2+2+2 = 6. 6 is a multiple of 3. 222 is divisible by 3.
yes - 91 times 9 is 819. It would be worth your while to learn how to divide by 9- ask your math teacher for a lesson.
21% of 819 = 819*21/100 = 171.99
819
819 is DCCCXIX
819 is a natural number
819-13 = 806
819 ÷ 39 = 21
922 - 819 = 103
819 ÷ 9 = 91