Is 87 a prime number?

1 Answer
Shwetank Mauria
Apr 2, 2016

87 is not a prime number but is a composite number.

Explanation:

To check whether a number is a prime number or not, one may take a number less than approximately its square root.

Here a number less than approximately the square root of 87 is 9, so one needs to try division of 87 by prime numbers up to number 9.

As prime numbers up to 9 are only {2,3,5,7} and number is divisible by 3 (one can check by using divisibility rule),

87 is not a prime number but is a composite number.

In fact 87=3xx29

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