What do you mean by can't see anybody number? Yappari contact is synchronize with your phone book.
1. If the person you want to see his/her number is in your phone book/contact list, you can always look his/her number phone book/contact list
2. If the person you want to see his/her number is not in your phone book/contact but you're chat with him/her directly, it will show up in Yappari recent chat
3. If the person you want to see his/her number is not in your phone book/contact and you're chatting indirectly (in a group), you can always look his/her number in yappari.log