Yep you read it right, its a whooping 16billion!!
That is the total amount of Lumens that Stellar has set aside to be claimed by Bitcoin holders. If you hold bitcoins, by the 26th of June 2017 and can proof ownership of the address by signing a signature, you will be awarded Lumens.
Stellar has published a lumens claims page where you can complete the process.
For futher information visit stellar.org