Please explain line no.6 in the program?

#1

how prateek bhaiya has given conditions for the loop? please explain. i am not gettin it

https://online.codingblocks.com/app/player/71388/content/110162/6831/lecture

#2

hello @Anku47
that line is genrating powers of 5.
that is 5 then 5*5 , then 5 * 5 * 5 …
in general after ith iteration it will generate 5^i.
now question is till when we should genrate this power of 5.

we should generate it till
n >= 5 ^i.
divide both sides with 5^i.
n/ (5^i) >=1

and that why bhaiya has given that conditon in loop.