Given that \( 9x^2 + 6xy + 4y^2 \) is a factor of \( 27x^3 - 8y^3 \), we can express:

\(27x^3 - 8y^3 = (3x - 2y)(9x^2 + 6xy + 4y^2)\)

Thus, the other factor is: 3x - 2y