Help Regarding Number Theory for Competitive Programming

Hi, I want to study Number Theory as it’s an important topic for competitive programming. And I know some basic number theory. When I google search for Number Theory there lots of resources which is available on the Internet after seeing that I am just confused what to study??. So please help me with selecting the right resources.

Please somebody give me the resources that can really help me.



for more guidance you can watch this video(hindi) :-

Thanks bro.