How long can you preserve sperm?

I was wondering how long can you perserve sperm in a sperm bank? Can you perserve it for hundreds of years? Thousands? Millions? Billions? How long will it last. I wonder this because could I technically have a child hundreds or thousands of years after I die, if my sperm is preserved in a sperm bank? How long can you preserve before it cannot create a child anymore? How many years? Please answer if you know. Thank You.

if they freeze it , it will last a 100 years or so but I think at a normal sprem bank they don't keep them that long

The sperm will start detirorating once its been out of the male, and if not frozen imediatly it will all die...making it useless...