4181

Number
$4181$ (four thousand, one hundred and eighty-one) is:


 * $37 \times 113$


 * The $19$th Fibonacci number, after $1$, $1$, $2$, $3$, $5$, $8$, $13$, $21$, $34$, $55$, $89$, $144$, $233$, $377$, $610$, $987$, $1597$, $2584$:
 * $4181 = 1597 + 2584$


 * The first composite Fibonacci number with a prime index:
 * $4181 = 37 \times 113$

Also see