So if we have the number 2384923482983, and this number in Chinese characters painted on a wall. Then if we take a picture of that wall, then that picture will have minimum as much entropy as the number itself? Or if I say out the number 2384923482983 in German and record it in an MP3 file, then that MP3 file will also have minimum as much entropy as the number itself?
Yes, provided the Chinese characters and the MP3 file have sufficient quality to make it possible to recover the number.