title: Checking for divisors till max{2 ≤ i ≤ n} (min (i,n/i))?
body: <p>My prof gave an alternative explanation for checking till sqrt(n) by replying this:</p>
  
  <p>"We need to check for divisors only till max<sub>2 ≤ i ≤ n</sub>(min(i, n/i)). 
  The maximum is attained when i = n/i, ie. i = sqrt n."</p>
  
  <p>What does he even mean? Can someone put it in English?</p>