It might appear like a pretty harmless sequence of numbers, but it's responsible for a major investigation by some of the more involved (obsessive) members of the Grand Theft Auto V community.
GTA player Karma Ingram recently shared his discovery via Twitter, noting that if the number was called from the in-game mobile whilst in single-player mode, it would trigger an explosion in the sky. You can watch it being demonstrated by Yan2295 below...
The contact name associated with the number is listed as 'Black Cellphones' - and the hunt is now on to discover what the number and its effects have in relation to the wider game.
You can join the discussion on this Reddit forum. Happy hunting.