4347

Number
$4347$ (four thousand, three hundred and forty-seven) is:
 * $3^3 \times 7 \times 23$


 * The $42$nd heptagonal number after $1$, $7$, $18$, $34$, $55$, $81$, $112$, $\ldots$, $3010$, $3186$, $3367$, $3744$, $3940$, $4141$:
 * $4347 = \ds \sum_{k \mathop = 1}^{42} \paren {5 k - 4} = \dfrac {42 \paren {5 \times 42 - 3} } 2$