Circumcision is obligatory in every Muslim male if he is still uncircumcised no matter what his age is. Uncircumcised Muslim male is not ritually impure though he is not allowed to perform Tawaf around the Ka'bah. He is allowed to perform all the other worship practices like Salah, fasting etc. preparing the body of your father after his demise is valid even if you are still uncircumcised. I advise you to get circumcised as soon as you can.
Wassalam.