Is 47 a prime number?

The number 47 is a prime. That means that its only positive factors are itself and 1. In other words, it cannot be divided evenly by any other numbers.

To test whether 47 is prime, a trick is to first find the smallest perfect square that is greater than 47. In this case, it is 7 x 7 = 49. Therefore, if 47 divides evenly into any numbers, one of the factors would have to be 7 or less. Then, it is easy to divide 47 by each of 2, 3, 4, 5, 6 and 7 to see that none of them divide evenly, meaning 47 must be prime.