The square root of -169 is not a real number; it is an imaginary number. Specifically, it can be expressed as:
\[ \sqrt{-169} = \sqrt{169} \cdot \sqrt{-1} = 13i \]
where \( i \) is the imaginary unit defined as \( i = \sqrt{-1} \).
Given this, since the square root of -169 is an imaginary number, it does not fit into the categories of rational numbers, whole numbers, integers, or irrational numbers. All those categories are subsets of real numbers, and the square root of a negative number does not belong to any of them.
If you need to place it somewhere, you would say it belongs in the category of complex numbers (which include imaginary numbers), but this option is not listed among the provided options. Therefore, none of the options given are correct.