[The Squatter of Amon Rûdh]

148,297.

We arrive at this answer by the application of Thû's Axiom, which in its simplest form works like this:

1. Pick a number, any number
2. Multiply by the square root of the top speed (in microns per hour) of your favourite Scalextric car.
3. Add the number of hairs on the most famous yak
4. Divide by the number of times your bank manager blinked in the last five minutes
5. Write the result on a piece of paper and pass it to the nearest person with an 'x' in their name. They should repeat steps 1-4 above.
6. Ask The Squatter of Amon Rûdh how many Balrogs it takes to illuminate a lightbulb.
7. Get a better evil henchperson name.

You can tell that I'm right because never in Tolkien's fiction do we see a Balrog in a situation where a lightbulb would be useful and a lightbulb has, in fact, been installed. This is clearly because in no version of the legends would there ever have been enough Balrogs, balrogs or balRogs (not to mention bAlrOgs) to power the number of bulbs required to make it a viable technology.

How many eagles does it take to install a doorbell?