How common is it to be related to royalty?

I am a 20th great-grandson of King Robert the Bruce of Scotland and a 23rd great-grandson of King Edward I (the Longshanks) of England. I am also a 34th great-grandson of King Alfred the Great of England. I am a 22nd great-grandson of King Phillip II of France. I am a So, I am directly related to English, Scottish, and the now non-existent French royalty.