3015

Number
$3015$ (three thousand and fifteen) is:


 * $3^2 \times 5 \times 67$


 * The $45$th pentagonal number after $1$, $5$, $12$, $22$, $35$, $\ldots$, $1820$, $1926$, $2035$, $2147$, $2262$, $2380$, $2501$, $2625$, $2752$, $2882$:
 * $3015 = \displaystyle \sum_{k \mathop = 1}^{45} \left({3 k - 2}\right) = \dfrac {45 \left({3 \times 45 - 1}\right)} 2$