# divisor

11. ### elementary divisor ring

Can anyone help me? I have a problem with proving a theorem for my thesis. Let R be a Hermite ring. If R/I is an elementary divisor ring, then R is an elementary divisor ring. Is it true? If that's true, I have no idea how to prove that lemma. Please help me.
12. ### How do I find the smallest proper divisor of large numbers?

For example, ( 22! + 1). I can't find examples in books or on the internet. Any help very much appreciated.
13. ### Greatest Common Divisor may be NP Complete (if so then P equals NP)

Clique (graph theory) - Wikipedia, the free encyclopedia (or any of the other interchangible views of NP Complete) has been called the hardest unsolved math problem and would likely result in solving all the remaining millenium problems if P equals NP and that is proven. On the other hand, most...
14. ### Summation of all proper divisor

What is the maximum 4 digit integer n for which the sum of its proper divisors is (n-1)? Thanks in advance
15. ### The greatest common divisor

The greatest common divisor 7571 and 2077
16. ### Greatest common divisor of an infinite set

Hello, help with the following problem would be greatly appreciated: We have an infinite set M =\{n^{13}-n| n \in \mathbb{N}\}, what is the greatest common divisor of all it's members? I have thought about this, and it seems since the power of n is 13 (And the period with which the numbers...
17. ### Greatest common divisor proof

Hello, would someone please help me with the following problem? Even small tips would be welcome. Let x, y, m, n, a, b, c, d be whole integers. The following applies: m = ax + by n = cx + dy ad - bc = 1 Prove that gcd(m,n) = gcd(x,y)
18. ### Greatest Common Divisor. Really hard problem.

There are three different integers: a,b,c > 1 which satisfy the condition GCD(a,b,c)=1. Find all possible values ??for GCD(a^2b+b^2c+c^2a, ab^2 +bc^2 +ca^2, a+b+c) I know that problem can be difficult, but I would be very grateful for any help. :D
19. ### greatest common divisor

Hello I have problem with finding the every possible value of number x, y, z \in Z GCD(x^2y+y^2z+z^2x, xy^2+yz^2+zx^2, x+y+z) when x,y,z > 1 and GCD(x, y, z) = 1 any ideas how to start?
20. ### Divisor function and Dircihlet

So I have constructed a table of all the non principal Dirichlet characters mod 16. Here is said table: Now, for each real-valued nonprincipal character ? mod 16, I want to veryify that: A(225) ? 1. A(n) = \Sigma ?(d) d|n Can anyone help? Thanks Here is the table mod 16...