I picked a bit with a toothpick and it seemed kinda powdery and like it was coming off. Can i pick it all off and then maybe wash it with some distilled water and a cloth?
I see some greenish patina but it fortunately does not look like the bronze disease that killed two of my Caligulas. I think it's probably OK, but will defer to those with more experience.
lordmarcovan is probably correct. Just keep an eye on the coin for a while. If you see a soft powder start to build up on the surface of the coin, then it is bronze disease and you will need to treat it. But I don't think you have anything to worry about.