Approximate Relations between Pi and Euler's Number/e to the pi root 163

Approximate Relation between $\pi$ (pi) and Euler's number $e$
This expression relating $e$ and $\pi$ comes within $10^{-12}$ of an integer:
 * $e^{\pi \sqrt {163} } \approx 262 \, 537 \, 412 \, 640 \, 768 \, 743 \cdotp 99999 \, 99999 \, 99250 \ldots$