The 54-year-old 'X Factor' boss said he is obsessed with numbers, reported Daily Star.
I have some quirky habits. Everything about me is about numbers so for some reason I am always counting numbers in the head. Even if I walk up the stairs I am counting how many steps and if it is 13 I make sure it is not going to be 13," Cowell said.
"So the last number cannot be 13. It can't be 67 either because 6 and 7 adds up to 13. So I will walk an extra step. It is a kind of sign of madness actually," he added.