Is 1002001 a prime number

Answer 1

1002001 is a composite number because it has more than two factors as it is divisible by 1, 1002001 and 11. There may exist many more factors other than 1, 1002001, and 11, but in order to show the given whole number is a Prime number, all we need to show is that it has more than two factors. There is no need to find all of the factors.

Test of divisibility by 11:

The sum of the digits of 1002001 which are at even places is 0 + 2 + 0 = 2.

The sum of the digits of 1002001 which are at odd places is 1 + 0 + 0 + 1 = 2.

The difference of those two numbers is 2 - 2 = 0.

Since the result of that difference is zero or a multiple of 11, the number is divisible by 11.