304

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


 * $2^4 \times 19$


 * The $6$th primitive abundant number after $20$, $70$, $88$, $104$, $272$:
 * $1 + 2 + 4 + 8 + 16 + 19 + 38 + 76 + 152 = 316 > 304$


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


 * The smallest positive integer which can be expressed as the sum of $2$ distinct lucky numbers in $18$ different ways


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


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