1, 11, 121.
11 is a common factor of 55 and 121.
One.
The number is 1.
One and 11.
1, 11, 121
The numbers 1, 121, and 11 all go into 121 evenly.
121 is an odd number and it is also a square number because 11*11 = 121
121 is not an even number.
121 is a square number
1,11,121
121 ÷ 11 = 11