Why 16 and any odd integer are relatively prime?

Question

I am about to use Euler's theorem , but I do not know Why 16 and any odd integer are relatively prime?

Could anyone explain this for me please?

Answer 1

What are the prime factors of $16$? Can any of them match a factor of an odd number?

Answer 2

Because $16=2^4$, but $n$ is odd and we have $$\gcd(16,n)=1$$