The only common factor is 1.
The common factors of 15 and 81 are 1 and 3
81 and 200 have no common prime factors.
The factors of 81 are 1, 3, 9, 27 and 81. For them to be common, they need to be compared to another set of factors.
The common factors of 72 and 81 are: 1, 3, and 9
34 and 81 share no common factors aside from 1.
The common factors of 81 and 99 are: 1, 3, 9
The common factors of 36 and 81 are: 1, 3, and 9
81 and 169 share no common factors aside from 1.
The factors of 81 are 1, 3, 9, 27, 81. For them to be common, they need to be compared to another set of factors.
The factors of 81 are 1, 3, 9, 27, 81. For them to be common, they need to be compared to another set of factors.
The common factors of 81 and 108 are: 1, 3, 9, and 27
The common factors of 81 and 135 are: 1, 3, 9, and 27