Welcome to Windows 7 Forums. Our forum is dedicated to helping you find support and solutions for any problems regarding your Windows 7 PC be it Dell, HP, Acer, Asus or a custom build. We also provide an extensive Windows 7 tutorial section that covers a wide range of tips and tricks.

Windows 7: What is a prime number?

 08 Jan 2020 #11 blue skies Windows 7 Home Premium 64 bit 119 posts Quote: Originally Posted by iko22 Write out the first n numbers along with the factors of n and watch the pattern : n factors of n 1 has factor of 1 2 has factors of 1 and 2 3 has factors 1 and 3 4 has factors 1, 2 and 4 5 has factors 1 and 5 6 has factors 1, 2, 3, 6 7 has factors 1, 7 8 has factors 1,2, 4, 8 9 has factors of 1, 3, 9 10 has factors 1, 2, 5, 10 11 has factors 1, 11 12 has factors 1, 2, 3, 4, 6, 12 13 has factors 1 and 13 14 has factors 1, 2, 7, 14 15 has factors 1, 3, 5, 15 Any number n, that has only factors of 1 and n, is a prime number. So, 1, 2, 3, 5, 7, 11 and 13 are prime numbers. A composite number is a positive number that has to have at least three possible factors. So, 4, 6, 8, 9, 10, 12, 14 and 15 are composite numbers. In algebra, a factor is any whole number that divides into another number an exact number of times. If you continue the sequence: 16 has factors of 1,2, 4, 8 and 16 so 16 is a composite number. 17 has factors of 1 and 17 and therefore 17 is another prime number. That was a much better answer than mine!! My System Specs