I can tell you from experience, I've turned down several acquihires in the last few months from giant companies, with no VC raised. It can happen if you're bootstrapped.
I don't want to pry too much, but do you have a team? Are these companies looking to hire just you or your IP? I am curious to hear more if you'd like to share.
The team is two founders and a contractor. Without talking specifics, the distinction between acquire and acquihire is IP/revenue/traction. Acquihire means "we don't care about your product, market or IP, but we do need talented engineers who demonstrate they can build".