Don't calculate when you can lookup! This will test almost a million numbers per second: 

c:\test>perl Math\Primes\First_1e6.pm
Found 122571 primes from 1000000 tries in 1.145 seconds (873362/s)

[download]
<Reveal this spoiler or all in this thread>

In reply to Re: Find prime number between 1 to 1000000 by BrowserUk
in thread Find prime number between 1 to 1000000 by mecrazycoder

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