“Numerous customers returned the garlic-flavored toothpaste.“ “Numbers of customers returned the toothpaste.” “Many of the customers.” Any of these is fine.
But “numerous of the customers”? Yuck.

“Numerous customers returned the garlic-flavored toothpaste.“ “Numbers of customers returned the toothpaste.” “Many of the customers.” Any of these is fine.
But “numerous of the customers”? Yuck.
