3654

Number
$3654$ (three thousand, six hundred and fifty-four) is:


 * $2 \times 3^2 \times 7 \times 29$


 * The $27$th tetrahedral number, after $1$, $4$, $10$, $20$, $35$, $\ldots$, $816$, $969$, $1140$, $1330$, $1540$, $1771$, $2024$, $2300$, $2600$, $2925$, $3276$:
 * $3654 = \ds \sum_{k \mathop = 1}^{27} \frac {k \paren {k + 1} } 2 = \dfrac {27 \paren {27 + 1} \paren {27 + 2} } 6$