President Donald Trump is celebrating his 73rd birthday Friday.
Born in 1946, Trump was the oldest President to be sworn into office. He took the oath at 70 years, 220 days old. Ronald Regan was sworn in at 69 years, 349 days old.
If President Trump completes a second term in office, he will become the oldest currently-serving President. Reagan was 77 years, 349 days old at the end of his presidency.