Nothing would beat the MGMAT Number Properties guide if you can buy it.
In fact, the free chapter 1 they provide online deals with exactly these concepts:
https://www.manhattangmat.com/pdf/np-4th.pdf
I'm sure it will clear up your concepts.
For practice of such problems, you will have to search for different number properties questions, as these concepts are involved in almost every other quant question. The GMATClub tests have 3 sets of HARD problems on Number Properties that I found useful to comb out my concepts.
~Abhay
Believe those who are seeking the truth. Doubt those who find it. -- Andre Gide