6601

Number
$6601$ (six thousand, six hundred and one) is:


 * $7 \times 23 \times 41$


 * The $6$th Carmichael number after $561$, $1105$, $1729$, $2465$, $2821$:
 * $\forall a \in \Z: a \perp 6601: a^{6600} \equiv 1 \pmod {6601}$


 * The $18$th Poulet number after $341$, $561$, $645$, $1105$, $1387$, $1729$, $1905$, $2047$, $2465$, $2701$, $2821$, $3277$, $4033$, $4369$, $4371$, $4681$, $5461$:
 * $2^{6601} \equiv 2 \pmod {6601}$: $6601 = 7 \times 23 \times 41$