Here's the link to the pre-stream tutorial on the topic, which also has the problemset:    • Number Theory for Competitive Program...  
Problemset link: codeforces.com/contestInvitation/bfde06ab8c7726cc3…
Problemset difficulties: pastebin.com/Tt26QKbM

Join this discord to find out when more streams will happen (because of school, they're definitely going to be inconsistent): discord.gg/ZcET622
Also join this organization: codeforces.com/ratings/organization/25096

Previous topic streams (including previous DP ones):    • Topic Streams  

My code templates: github.com/galencolin/cp-templates