805

Number
$805$ (eight hundred and five) is:


 * $5 \times 7 \times 23$


 * The $23$rd second pentagonal number after $2$, $7$, $15$, $26$, $\ldots$, $222$, $260$, $301$, $345$, $392$, $442$, $495$, $551$, $610$, $672$, $737$:
 * $805 = \dfrac {23 \left({3 \times 23 + 1}\right)} 2$