304

Number
$304$ (three hundred and four) is:


 * $2^4 \times 19$


 * The $7$th primitive semiperfect number after $6, 20, 28, 88, 104, 272$:
 * $304 = 1 + 2 + 16 + 19 + 38 + 76 + 152$


 * The $50$th nontotient:
 * $\nexists m \in \Z_{>0}: \phi \left({m}\right) = 304$
 * where $\phi \left({m}\right)$ denotes the Euler $\phi$ function


 * The $23$rd untouchable number after $2, 5, 52, 88, 96, 120, 124, \ldots, 262, 268, 276, 288, 290, 292$.