GOOG has 118k FTE (https://finance.yahoo.com/quote/GOOG/profile?p=GOOG)
APPL has 137k FTE (https://finance.yahoo.com/quote/AAPL/profile?p=AAPL)
AMZN has 798k FTE (https://finance.yahoo.com/quote/AMZN/profile?p=AMZN) Note: this seems incorrect.
INTC has 110k FTE (https://finance.yahoo.com/quote/INTC/profile?p=INTC)
HPQ has 56k FTE (https://finance.yahoo.com/quote/HPQ/profile?p=HPQ)
But there are jobs where you'd have the possibility to do this in industries that will take some re-arranging to make it work. Legal and financial for instance, call centers (some technical issues), most design and creative work.
The impossible ones are anything involving care, production and logistics. Even retail could in principle be done but it would require a massive shift on the part of the consumer. Going shopping is very much ingrained and retooling that industry for home delivery is neither fast nor simple when done on a massive scale.
We did some work with IBM a few years ago and my boss said when he went for an on-site visit it was basically a giant office building that was mostly vacant.