In addition to the excellent explanation offered in Sugarbrie's post,let me mention something else.
Many of us find these numbers hard to keep straight and classical publishers(especially pre-electronic aged) sometimes named compositions for the convenience of their customers who ordered music from them.
Here are just a few:
--Mozart, Jupiter Symphony,Emporor Concerto
--Hayden,Suprise,Drumroll,and Bear Symphonies
--Beethoven,Moonlight Sonata,Pastoral Symphony
I could go on but you get the idea.
That a piece of music had a publisher assigned nickname meant that it was popular among buyers and does not guarantee you will like it, but that many others did,whatever that is worth.