4141

Number
$4141$ (four thousand, one hundred and forty-one) is:
 * $41 \times 101$


 * The $41$st heptagonal number after $1$, $7$, $18$, $34$, $55$, $81$, $112$, $\ldots$, $3010$, $3186$, $3367$, $3744$, $3940$:
 * $4141 = \ds \sum_{k \mathop = 1}^{41} \paren {5 k - 4} = \dfrac {41 \paren {5 \times 41 - 3} } 2$