The number 7 is seen as lucky in slots and pop culture because it often...

https://www.bravobookmarks.win/the-number-7-is-seen-as-lucky-in-slots-and-pop-culture-because-it-s-tied-to

The number 7 is seen as lucky in slots and pop culture because it often represents good fortune and completeness. For example, the classic "777" on slot machines signals a big win