But first, the '197'.
Trump gave his victory speech, April 26, 2016, Melania Trump's birthday, 197-days before winning the Presidential "selection". 197, the 45th prime
If you read below, the 'and' is left out of the 'United States' title, meaning in the U.S., it is '187'.
His GOP Convention in Cleveland began July 18, or 18/7, 187-days from Inauguration Day.