Question: "How many denominations are there within Christianity at large?"
You may be surprised to find out that Wikipedia (the theological factbook — haha) states:
This is not a complete list, but aims to provide a comprehensible overview of the diversity among denominations of Christianity. As there are reported to be approximately 38,000 Christian denominations,Let's remember what Paul says about the true and undeniable gospel:
1 Corinthians 15:1-4 Now I make known to you, brethren, the gospel which I preached to you, which also you received, in which also you stand, 2 by which also you are saved, if you hold fast the word which I preached to you, unless you believed in vain. 3 For I delivered to you as of first importance what I also received, that Christ died for our sins according to the Scriptures, 4 and that He was buried, and that He was raised on the third day according to the Scriptures,