strange properties of 666

Incredibly, the number 666 is equal to the sum of the digits of its 47th power, and is also equal to the sum of the digits of its 51st power. That is,

666^47 = 5049969684420796753173148798405564772941516295265
408188117632668936540446616033068653028889892718859670297
563286219594665904733945856

666^51 = 9935407575913859403342635113412959807238586374694
310089971206913134607132829675825302345582149184809607489
72838900637634215694097683599029436416

and the sum of the digits on the right hand side is, in both cases, 666. In fact, 666 is the only integer greater than one with this property. (Also, note that from the two powers, 47 and 51, we get (4+7)(5+1) = 66.)

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