The wordplay idea is overrated imo, there are better options to come up with creative bounties :D
Silvers Rayleigh - 3.047.000.000 - He should be above 3b (and for those who criticize the number for being higher than Blackbeard's current one: Teach's bounty is his first one and even though he's a Yonko he needs to be in this position for a longer time and prove himself).
The 47 is the atomic number for silver.
Dracule Mihawk - 2.189.700.000 or 3.189.700.00 - Probably the 2b, but I think he deserves the 3b as well as Rayleigh.
1897 was the release year of Bram Stoker's Dracula.
Blackbeard - currently 2.247.600.000, could be 5.047.000.000
His current 47 is still in the bounty and his new one would be Whitebeard's bounty plus 1m, making Blackbeard's bounty the highest of all known Yonko bounties.
:)