268

Number
$268$ (two hundred and sixty-eight) is:


 * $2^2 \times 67$


 * The $26$th noncototient after $10, 26, 34, 50, \ldots, 206, 218, 222, 232, 244, 260, 266$:
 * $\nexists m \in \Z_{>0}: m - \phi \left({m}\right) = 268$
 * where $\phi \left({m}\right)$ denotes the Euler $\phi$ function


 * The $18$th untouchable number after $2, 5, 52, 88, 96, 120, 124, 146, 162, 188, 206, 210, 216, 238, 246, 248, 262$.