34

Number
$34$ (thirty-four) is:
 * $2 \times 17$


 * The $9$th Fibonacci number, after $1, 1, 2, 3, 5, 8, 13, 21$:
 * $34 = 13 + 21$


 * The $3$rd noncototient:
 * $\nexists m \in \Z_{>0}: m - \phi \left({m}\right) = 34$
 * where $\phi \left({m}\right)$ denotes the Euler $\phi$ function


 * The magic constant of the order $4$ magic square.

Also see

 * Magic Constant of Order 4 Magic Square