163

Number
$163$ (one hundred and sixty-three) is:


 * The $38$th prime number


 * The $9$th prime number after $53$, $71$, $103$, $107$, $109$, $149$, $151$, $157$ which cannot be expressed as either the sum of or the difference between a power of $2$ and a power of $3$


 * The $33$rd lucky number:
 * $1$, $3$, $7$, $9$, $13$, $15$, $21$, $\ldots$, $115$, $127$, $129$, $133$, $135$, $141$, $151$, $159$, $163$, $\ldots$


 * This expression relating $e$ and $\pi$ comes within $10^{-12}$ of an integer:
 * $e^{\pi \sqrt {163} } \approx 262 \, 537 \, 412 \, 640 \, 768 \, 743 \cdotp 99999 \, 99999 \, 99250 \ldots$

Also see

 * Approximate Relations between $\pi$ and $e$: $e^{\pi \sqrt{163} }$