What is the Remainder of 2 to the Power of 1000005 Divided by 55?

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Homework Statement



i need to obtain the remainder of the divison 2^{1000005} divided by 55

Homework Equations



Euler theorem 2^{\phi (55)}=1 mod(55)



The Attempt at a Solution



my problem is that applying Euler theorem i reach to the conclusion that the remainder is the same as the value 'a' inside the congruence equation

2^{5}=a mod(55) but it would give me that a is negative ¡¡

it gives me a=-23 or similar using congruences or a =32
 
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phi(55) = 4*10=40

So, 2^40 = 1

1000005 = 1000000 + 5 which Modulo 40 is 5

So 2^2000005 = 2^5 = 32.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...

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