Prime Curios!: 168

168
(another Prime Pages' Curiosity)

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The number of primes less than or equal to a thousand (

(1000) = 168) equals the number of hours in a week (7 x 24 = 168). [Honaker]

168 = sigma( sigma (sigma( 1+6+8 ))) and 1+6+8 = (1*6*8). Note that 168 is the second number with this property. [Firoozbakht]