what is Niall Horans fan #?

[Miranda]

Im talking about like his actual # not a pizza hut #

[Conqueror Worm ©]

For Twitter?

Enter his name into the search option on Twitter and you will see every tweet involving his name. Look for accompanying hashtags (which is how the # is named).

OR

Join a fan club on Twitter devoted to him.

OR

Start your own hashtags. If you have lots of followers, it may actually start to trend on Twitter.