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, 29
1, 31
They are: 2 and 11
1, 2, 11 and 22
1, 7, 13, 91.
1, 3, 11, 33.
1, 3, 7, and 21 are.
2, 5, 10, 25
1, 2, 4, 8, 16.
Its prime factors are 2 and 3
1, 2, 4, 31, 62, 124.