Sure. Any 1-digit number contains only one-digit numbers as factors. Any larger number, on the other hand, contains itself as a factor, so these can be excluded.
1,2,23 and 46 are the only even factors of 46 so this is impossible
6 is the only single digit perfect number.
81 is.
63? But it has more than two one-digit factors.
1 [trivially], 2, 3, 4, 5, 6, and 7.
One through nine all have single digit factors.
All numbers have factors. Some factors have one digit. The factors of 24 are 1, 2, 3, 4, 6, 8, 12, 24 The single digit factors of 24 are 1, 2, 3, 4, 6 and 8.
1, 2, 4, 5, 8
1, 2, 3, 4, 6, 7
1, 2, 3, 4, 6, 8
2100
Sure. Any 1-digit number contains only one-digit numbers as factors. Any larger number, on the other hand, contains itself as a factor, so these can be excluded.
As a product of its prime factors in exponents it is: 22*3*52*7 = 2100
1, 2, 3, 4, 6, 8, 9.
1
1 is a single digit, 0 is the absence of a digit.