To divide \( 3639 \) by \( \sqrt{913} \), you would express the division as:
\[ \frac{3639}{\sqrt{913}} \]
To rationalize the denominator, multiply both the numerator and the denominator by \( \sqrt{913} \):
\[ \frac{3639 \cdot \sqrt{913}}{\sqrt{913} \cdot \sqrt{913}} = \frac{3639 \cdot \sqrt{913}}{913} \]
So, the exact answer is:
\[ \frac{3639\sqrt{913}}{913} \]
This is the exact representation of the division.