He is also said to have done a deal for an investment bank to buy bonds backed by his TV franchises.
His riches come despite Cowell making a decision to scale back his work in recent years to spend more time with his partner Lauren Silverman, 46, and their 10-year-old son Eric.
He now sticks to a four-day week as he believes working on a Friday is “pointless”.
Former workaholic Cowell – who has also changed his sleeping and eating patterns – told The Sun about his lifestyle overhaul: “Actually, the first thing (I do) is take off Fridays.
”Don’t work on Fridays, because you don’t have to.
”Eat dinner at five o’clock. Don’t take calls after 5.30pm. Don’t read emails after 5.30pm. Watch a happy movie.
”And stay outside. I’m not kidding about the Fridays. I don’t think anyone should be working five days a week. It’s just pointless.”