5671

Number
$5671$ (five thousand, six hundred and seventy-one) is:


 * $53 \times 107$


 * The $106$th triangular number after $1$, $3$, $6$, $10$, $15$, $\ldots$, $5253$, $5356$, $5460$, $5565$:
 * $5671 = \displaystyle \sum_{k \mathop = 1}^{106} k = \dfrac {106 \times \left({106 + 1}\right)} 2$