AES Inverse Key Schedule I have a 128-bit input-block and the corresponding cipher-block given.
Additionally I have the last round-key given. 
Is it now possible to get (calculate) the associated cipher-key? I already implemented the normal key-schedule with the rcon to generate the round-keys out of a cipher-key (like on wikipedia: https://en.wikipedia.org/wiki/Rijndael_key_schedule), but it didn't help me much for the other way... 
Ist the AES Key Schedule easily invertible? I'm a bit baffled now because i thought it would be.

Thanks in advance for your answers.
Yes, that is possible: It is quite obvious from the description of the key schedule that all involved operations are invertible. An implementation of that inversion is the function aes128_key_schedule_inv_round found in this C file.