An 11g packet of dry yeast, according to microscopic counts, contains somewhere around 220+ billion cells.
From the Q&A on Danstar's website -
2) Setting aside viability, what is the typical actual total cell count per gram Nottingham?
I did a count some time ago, and though my methods are very crude and homemade (using estimates drop volumes), and may give errors, I arrived at a much higher count, around 20 billion/g. It did only one count, so there may have been error, but I am doubtful that my error is that large, or if the numbers you guarantee are rather on the low side to be safe? I never repeated the experiment so I could have been in error, but it would be nice if you can confirm what is the excepted actual total cell count, rather than the minimum guaranteed viable cell count)
The viabilities mentioned on the technical data sheets are minimum viable cells per gram that we guarantee determined by plate count on YPD-agar. Usually the viability is higher. There is a slight difference in how resistant the different strains are to drying and rehydration. Usually ale yeast strains are more resistant than lager yeast strains.
You might also consider that you will find much higher cell numbers under the microscope than by plate count, even if you have 100 % viability because you do not always have a single cell forming a colony but rather two or more cells. For Nottingham yeast the average cell count under the microscope is around 20 to 30 billion cells per gram dry yeast.