6533

Number
$6533$ (six thousand, five hundred and thirty-three) is:
 * $47 \times 139$


 * The $47$th octagonal number, after $1$, $8$, $21$, $40$, $65$, $\ldots$, $3816$, $4033$, $4256$, $4485$, $4720$, $4961$, $5208$, $5461$, $5720$, $5985$, $6256$:
 * $6533 = \displaystyle \sum_{k \mathop = 1}^{47} \left({6 k - 5}\right) = 47 \left({3 \times 47 - 2}\right)$