RSA attack excercise I am a beginner in cryptography. I studied the RSA algorithm and now I want to solve an exercise. 

Cipher Text (HEX): 41A387CABD1C144C99E4B44CE2812A7696CE8A9B5941164741E91B82D89886700DD73A61C580BD75DFC0351D3D6BBF644408A77CB421A115C5
Public Key (e, n): (4049, 16395979)


If:

n = p*q
z= (p-1)*(q-1)
e*d mod z =1


And after trying I found:

q = 3659
p = 4481
z = 16387840
d = 10118449


Now,
1) Is it correct value for d(secret key)?
2) I know that I should compute $c^d mod n$, But c is very big hex! How can I do it? Should I split it first?
You could check, if $e\cdot d\equiv 1 (\bmod z)$. [1] Since your $z=\phi(n)$ and you want to do something like $(m^e)^d \bmod n= m^{ed} \bmod n \overset{!}{\equiv} m$. Therefore, $ed\equiv 1 (\bmod z)$

For decryption check cryptool. [2]

[1] https://en.wikipedia.org/wiki/Fermat%27s_little_theorem#Generalizations
[2] https://www.cryptool.org/