1035

Number
$1035$ (one thousand and thirty-five) is:


 * $3^2 \times 5 \times 23$


 * The $45$th triangular number after $1$, $3$, $6$, $10$, $15$, $\ldots$, $496$, $528$, $561$, $595$, $630$, $666$, $703$, $741$, $780$, $820$, $861$, $903$, $946$, $990$:
 * $1035 = \displaystyle \sum_{k \mathop = 1}^{45} k = \dfrac {45 \times \left({45 + 1}\right)} 2$


 * The $23$rd hexagonal number after $1$, $6$, $15$, $28$, $45$, $66$, $91$, $\ldots$, $703$, $780$, $861$, $946$:
 * $1035 = \displaystyle \sum_{k \mathop = 1}^{23} \left({4 k - 3}\right) = 23 \left({2 \times 23 - 1}\right)$