I don’t want to be pedantic about the presidency of Donald J Trump but …
… the media is wrong when it describes him as the 45th President of the United States.
The first United States President was George Washington, who served from 1789-1797, so that the current President Donald Trump is the 44th to hold the office. However, there have been 45 presidencies. Grover Cleveland was the 22nd and 24th President and therefore was the only US president to serve two non-consecutive terms (1885-1889 and 1893-1897) and to be counted twice in the numbering of the presidents.
If you want to know more about the election, duties and powers of the US president, check out my guide here.