An irrational number cannot be expressed as a simple fraction (i.e., as the ratio of two integers), and its decimal representation does not terminate or repeat.
From the list you provided, the only irrational number is:
- \( \sqrt{3} \)
The other numbers (4, 52.781654292, 3.6363636363636363..., -7, 8, 37) are all rational because they can either be written as a fraction or their decimal representations are either terminating or repeating. Specifically, 3.6363636363636363... is a repeating decimal, which still qualifies as a rational number.
Thus, the answer is:
\[ \sqrt{3} \]