To find the product of \( 5 - \sqrt{16} \) and \( 16 \), we first need to simplify the expression.
Since \( \sqrt{16} = 4 \), we have:
\[ 5 - \sqrt{16} = 5 - 4 = 1 \]
Now, we multiply this by \( 16 \):
\[ 1 \times 16 = 16 \]
The number \( 16 \) is a rational number since it can be expressed as a fraction \( \frac{16}{1} \).
Thus, the answer is:
16; a rational number.
(Note: The answer options provided in the question do not contain "16; a rational number." Based on the calculation, you may need to choose the correct response if available, or the answer has to be inferred.)