1, 3, 7, and 21 are.
1, 2, 4, 5, 10, and 20
x2-7x+12 (x-3)(x-4)
The common factor of both 15 and 27 is 3.
36=4x9=2x2x3x3, or, if you like, 36=6x6=2x3x2x3
The largest factor of any positive number is the number itself.
1, 31
1, 29
They are: 2 and 11
1, 2, 11 and 22
2, 5, 10, 25
1, 7, 13, 91.
1, 3, 11, 33.
1, 3, 7, and 21 are.
Its prime factors are 2 and 3
1, 2, 4, 8, 16.
1, 2, 4, 5, 10, and 20