222

Number
$222$ (two hundred and twenty-two) is:
 * $2 \times 3 \times 37$


 * The $12$th second pentagonal number after $2, 7, 15, 26, 40, 57, 77, 100, 126, 155, 187$:
 * $222 = \dfrac {12 \left({3 \times 12 + 1}\right)} 2$


 * The $21$st noncototient after $10, 26, 34, 50, 52, 58, 86, 100, 116, 122, 130, 134, 146, 154, 170, 172, 186, 202, 206, 218$:
 * $\nexists m \in \Z_{>0}: m - \phi \left({m}\right) = 222$
 * where $\phi \left({m}\right)$ denotes the Euler $\phi$ function


 * The $2$nd element of the $2$nd set of $4$ positive integers which form an arithmetic progression which all have the same Euler $\phi$ value:
 * $\phi \left({216}\right) = \phi \left({222}\right) = \phi \left({228}\right) = \phi \left({234}\right) = 72$


 * The $13$th of the $17$ positive integers for which the value of the Euler $\phi$ function is $72$:
 * $73, 91, 95, 111, 117, 135, 146, 148, 152, 182, 190, 216, 222, 228, 234, 252, 270$