It's definitely a cast replica, not a genuine ancient coin, sorry.
In this case, it's actually a copy of a copy: it's a cast replica of a Renaissance-era fake sestertius of emperor Commodus, made by Cavino - there are
genuine coins with this same Salus reverse design, but they look quite different to these "Paduan" fakes. A more realistic-looking Paduan replica with this design ended up in the British Museum long ago;
they still have it.
"Genuine Paduans" - replicas that are actually hundreds of years old - are collector items in their own right today, and can themselves be worth close to what a genuine coin would be worth. Unfortunately, yours is definitely not an authentic Paduan.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis