What type of number has no factors other than 1 and itself?

More Questions:

What fashion designer owns Maxim's restaurant in Paris?

Where on your pants can you often find the initials YKK?

What song about her age did Charmain Carr sing in the movie version of "The Sound of Music"?

Where is the most dangerous type of thunderstorms?

What color is a polar bear's skin?

In the TV show "The Simpsons', which character is allergic to regular milk?

Whose California grave marker reads "1935 - 1998 And the Beat Goes On?'

Which TV character owns a talking cat called Salem?

In the TV show "The Simpsons', Groundskeeper Willie comes from what country?

What general led the Confederates at the Battle of Gettysburg?

The fortification at West Point were originally built during what war?

Who was the only clean-shaven US president in the fifty years between Grant and Taft?

What US state has been governed by Benjamin Butler and Edward Everett?

What year did Buddy Holly die in a plane crash?

In which sea would you find the island of Bornholm?