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The nth Prime Page will now find any of the first 2.623˙10^{15} primes or
π(x) for x up to 10^{17}. Single Curio View: (Seek other curios for this number) 21 is the only known multidigit number m such that both numbers m * m!  prime(m) and m * m! + prime(m) are primes. [Firoozbakht]
Submitted: 20040911 03:35:00; Last Modified: 20080922 21:22:12.
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