I follow the rule: your keys, your crypto, so do whatever you want with them. Assuming, of course, that this situation is true, because it's hard to believe that someone sends such an amount to an unknown address.
If this happened to me, it is an amount that would definitely allow me to change my current life and I would not hesitate for a moment to properly manage these funds. I would pay my taxes honestly, then buy a new house, a car, and invest the rest.