5

This number is a prime.

Just showing those entries submitted by 'Laurv': (Click here to show all)

5 stays in the middle of every magic square of order 3. Note that the magical sum for such a square is 5*3. [Laurv]

5 is the smallest number that appear in two twin Pythagorean triplets: (3, 4, 5) and (5, 12, 13). [Laurv]

5 is the smallest hypotenuse of a Pythagorean triangle (3^2 + 4^2 = 5^2). [Laurv]