It's clearly 67.
secretly a lot of drivers are chosen by the number designers of the cars. When Vettel left Ferrari, they had a ton of 5's left, so, Sainz it was. Same with Sauber. With the amount of stickers left, Bottas was a cheap option.
For Mercedes, there were still some 6's left at the back of the factory, that combined well with the 7's left from Bottas.
RedBull of course lifted it to a whole different level. With Ricciardo having the number three, as a streamlined team as they are, Verstappen was the obvious choice because they were running out of 2's and 6's. When it was clear that Verstappen would become world champion then they really went into overdrive! They headed for a team with the numbers 1 and 10, when that didn't work out they tried 1,23. Finally succes with 1,11.
Lando Norris to Mercedes in the near future seems to be secured!