More numbers! How fun!
Two the word comes from Old English, where there are actually different versions of it: twa, the feminine form and twegen, the masculine version. Boy, am I glad English lost the gendering of words. It’s annoying enough without it. Both versions come from the Proto Germanic twa, so I guess we know what version is the real version. Before that, it was the Proto Indo European duwo/dwo. Which then gave a ton of other languages their word for two as well.
So that’s the word. What about the character?
There were forms of counting in lots of primitive cultures, but India seems to have been the first place to use a unique symbol to represent a number. The Hindu 2 actually looks remarkably similar to ours—maybe it’s a bit curlier. One theory for why it looks the way it does is that originally it was two dashes (like a = sign) and people writing it started connecting the two bars because it was easier. Think about it. Try writing out a = sign, but don’t take your pen off the surface when you’re moving between the two bars. It looks like a Z, which looks like a 2. Yes, laziness may have given us the symbol.
That wouldn’t surprise me at all.
Tony Jebson’s page on the Origins of Old English