It's not even close.
So let's do some simple math. A sand grain is defined as having a range of sizes, but 1mm diameter is typical. So for simplicity let's use that size.
The earth has an average radius of 6371km. This gives the earth a surface area of 1.28 times 10^14 square millimeters of surface area.
There are 7 times 10^22 stars. Divide this by the surface area of the earth and we learn how deep the sand across the entire earth would have to be to equal the number of stars.
The depth is 550km.
So it seems reasonable to conclude that there are more stars than there are grains of sands on all the beaches.
I'm having troubles following your math.
Earth: 6371km radius.
Surface area of a sphere: 4πr
^{2}That gives us a surface area of:
4*π*(6371)
^{2} = 5.1 x 10
^{8} km
^{2}1000x1000 mm
^{2} in a m
^{2}1000x1000 m
^{2} in a km
^{2}So that gives us 10
^{12} mm
^{2} in a km
^{2}So we get the surface area of the earth being about 5.1 x 10
^{20} mm
^{2}So, the difference between the number of stars and the number of square mm on the planet surface is only a factor of 10
^{2} (assuming the accuracy of all the estimates).
or, about 100mm, or about a shell 10cm thick.
So, the question is how much of the earth is covered by sand.
Beaches
Sand Dunes
Great Deserts
Ocean Floor
Mountains
Sandstone
Component of dirt
Loam
Etc.
I think you would find out that you would have more than adequate sand to cover the earth several times over with 10cm of sand.
(Oh, it looks like piktor67 was on the same track).