4720

Number
$4720$ (four thousand, seven hundred and twenty) is:


 * $2^4 \times 5 \times 59$


 * The $40$th octagonal number, after $1$, $8$, $21$, $40$, $65$, $\ldots$, $3008$, $3201$, $3400$, $3605$, $3816$, $4033$, $4256$, $4485$:
 * $4720 = \ds \sum_{k \mathop = 1}^{40} \paren {6 k - 5} = 40 \paren {3 \times 40 - 2}$