What is the oldest man-made object still in Earth orbit?

Factual Questions
1

Is there still anything from the early days of the space-race still in orbit? Or would all of the “early” satellites long since have plummeted back to Earth?

Bonus points for the oldest, still functioning satellite.

Thanks

2

How about Vanguard I?

3

Looks like the oldest functional man-made object in space is Pioneer 6. It’s not in Earth orbit, however.