To simplify \( 4^9 \cdot 4^{-7} \), we can use the properties of exponents. Specifically, the property states that when multiplying two powers with the same base, you add the exponents:
\[ 4^9 \cdot 4^{-7} = 4^{9 + (-7)} = 4^{9 - 7} = 4^2 \]
Now, we can compute \( 4^2 \):
\[ 4^2 = 16 \]
Therefore, the numerical equivalent of \( 4^9 \cdot 4^{-7} \) is \( 16 \).
So the correct answer is: 16.