What are the common factors of 54 and 81?

54 = 2 x 3^3

81 = 3^4

Therefore factors of 54 are:

1

2

3

6 = 2 x 3

9 = 3^2

18 = 2 x 3^2

27 = 3^3

54

Factors of 81 are:

1

3

9 = 3^2

27 = 3^3

81

Common factors are thus:

1, 3, 9, 27