There are 278 5-digit numbers less than 20,000 that are divisible by both four and nine.
There are 21 two-digit prime numbers.
None. 3 digit numbers are not divisible by 19 digit numbers.
It would help to know which digit. 0 appears in 9 numbers and each of the others in 18 numbers.
17
90
90
The 3 digit numbers under 500 are 100 through 499.
149 of them.
4,000 even numbers, 4,000 odd numbers.
I believe there are 2 positive three-digit perfect cube numbers, that are even.
There are 294 such numbers.
900 numbers from 100 to 999
There are no pairs of 2-digit numbers with a difference of 90 if both numbers are positive or both negative. However, with one positive and one negative, there are 71 pairs.
All the numbers from 10 to 99 are positive 2 digit integers
102 = 100 which is the first possible three digit number that is a perfect square. 312 = 961 which is the last possible three digit number that is a perfect square. So there are 22 three digit positive numbers that are perfect squares.
-27