This number is a composite.
Q: Is 9991 prime? A: 9991 = 10000 – 9 = 100^2 – 3^2 = (100 – 3)(100 + 3) = 97 * 103. Therefore, the number 9991 is composite. [Haratis]
Q: Is 9991 prime? A: 9991 = 10000 – 9 = 100^2 – 3^2 = (100 –
3)(100 + 3) = 97 * 103. Therefore, the number 9991 is
composite. [Haratis]