45
A 4-digit number divisible by both 5 and 9 must be divisible by their least common multiple, which is 45. To find a 4-digit number divisible by 45, we need to find a number that ends in 0 and is divisible by 45. The smallest 4-digit number that fits these criteria is 1005 (45 x 22 = 990, and adding 15 gives us 1005).
The number is 45
99,990.
There are 45 such numbers.
999990
123, three number 45, two number
100000 2847239582
90000, for example.
45
If the number's last digit is 0, then it is divisible by 10. e.g. 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 and so on are all divisible by ten. but... 45 is not divisible by ten because the last digit is not zero.
525