Is Prime

Check if a number is a prime number by testing divisibility up to its square root.

Code

Algorithms
$isPrime = $num > 1;
for ($i = 2; $i <= sqrt($num) && $isPrime; $i++) { if ($num % $i === 0) $isPrime = false; }
$isPrime ? 'true' : 'false';

Parameters

The number to check

Server

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