answersLogoWhite

0

Sum of the digits of 87 = 8+7 =15(a multiple of 3) which means that 87 is divisible by 3.

Therefore, 87 is not a Prime number as it has more than two factors which are 1, 87, 3 etc.

In order to prove that a given number is prime we shall show that the given number has more than two factors. There is no need to find all the factors.

User Avatar

Wiki User

14y ago

What else can I help you with?