945

Number
$945$ (nine hundred and forty-five) is:


 * $3^3 \times 5 \times 7$


 * The $1$st odd abundant number:
 * $\map {\sigma_1} {945} - 945 = 975 > 945$


 * The $14$th primitive abundant number after $20$, $70$, $88$, $104$, $272$, $304$, $368$, $464$, $550$, $572$, $650$, $748$, $836$:
 * $1 + 3 + 5 + 7 + 9 + 15 + 21 + 27 + 35 + 45 + 63 + 105 + 135 + 189 + 315 = 975 > 945$


 * The $19$th primitive semiperfect number after $6$, $20$, $28$, $88$, $104$, $272$, $304$, $350$, $368$, $464$, $490$, $496$, $550$, $572$, $650$, $748$, $770$, $910$:
 * $945 = 1 + 5 + 7 + 9 + 15 + 21 + 35 + 45 + 63 + 105 + 135 + 189 + 315$

Also see

 * Primitive Semiperfect Number: 945