many many.....But just 3500 in common use，so you just need to learn the basic words.

you just need to know about two thousand ,you can reading,writting,talking,but you must know mush about themslves. less than english,right?

If you divide each character in one, two, three or four parts, you will notice it has a rule of how to form a character (as water 水, metal 金, fire 火 ..., etc.) So you can imagine its property, 沙 (formed by 2 parts, "water 水" and the word " 少few " , "a few of water" , and the word means "sand"). This shows that the word is made always by the same words, just in different places and different pronunciations. Bye bye.

Very wise question! I have an abridged dictionary which contains over million characters. Well, I think what you want to know is "how many characters do you need to use Chinese functionally?" I would say about 600-1000 for travelling is enough. Hope, it helps. ;)

My guess is there are as many chinese characters as english words.