741

Number
$741$ (seven hundred and forty-one) is:


 * $3 \times 13 \times 19$


 * The $38$th triangular number after $1$, $3$, $6$, $10$, $15$, $\ldots$, $325$, $351$, $378$, $406$, $435$, $465$, $496$, $528$, $561$, $595$, $630$, $666$, $703$:
 * $741 = \ds \sum_{k \mathop = 1}^{38} k = \dfrac {38 \times \paren {38 + 1} } 2$