The YouTube channel Atlas Pro just released a terrific video called "The Geography of Yohanan", which raises an excellent point. Mohammed is often credited as being the most common name in the world, but there's a hidden name which might have even greater spread. Yohanan is a Hebrew word meaning "God is gracious", and just as Mohammed spread with Islam, Yohanan spread with Christianity to countries all over Europe. It spent the longest time in Greek, where variations such as Yanni and Gianni arose. Then Iohannes was borrowed into Latin, and the name's development skyrocket from there.
...Among many others. At the very least, all these variations of Yohanan are comparable to the extent of Mohammed - and that's not even considering all the last names like Jackson and Johnson. It's crazy how a name none of us recognize today is potentially held by the most people in the world. Onomastics (the study of name origins) is a very interesting subfield of etymology!
Adam Aleksic, a freshman studying linguistics at Harvard University, has been described as the internet's sixth most famous etymologist. He also has disturbing interests in words, vexillology, geography, board games, limericks, and law.