All of them.
there are 899 whole numbers that have three digits.
525
Every whole number can be multiplied by 3..
Numbers above 99 and under 1000 are 3-digits, all 900 of them.
Infinitely many.
I believe the factors/digits would have to be either 1, 1, 2, 3 (12 combinations) or 1, 1, 1, 6 (4 combinations).
900
2*3*3*3*3 = 162
from 3 digits (10x10) to 4 digits (99X99)
There are no 3-digit whole numbers whose digits sum to 3. The smallest 3-digit number is 100, and the largest is 999, but in neither case is the sum of the digits equal to 3.
There are 5 numbers of 1 digit, 25 numbers of 2 digits, and 75 numbers of 3 digits. This makes 105 numbers in all.
8 digits just count the amount of numbers.