290

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Number

$290$ (two hundred and ninety) is:

$2 \times 5 \times 29$


The $21$st untouchable number after $2$, $5$, $52$, $88$, $96$, $120$, $124$, $\ldots$, $262$, $268$, $276$


The $28$th noncototient after $10$, $26$, $34$, $50$, $\ldots$, $244$, $260$, $266$, $268$, $274$:
$\nexists m \in \Z_{>0}: m - \map \phi m = 290$
where $\map \phi m$ denotes the Euler $\phi$ function


The $32$nd sphenic number after $30$, $42$, $66$, $70$, $\ldots$, $246$, $255$, $258$, $266$, $273$, $282$, $285$, $286$:
$290 = 2 \times 5 \times 29$


The $47$th nontotient:
$\nexists m \in \Z_{>0}: \map \phi m = 290$
where $\map \phi m$ denotes the Euler $\phi$ function


Also see