President Truman was the 33rd president and he was literally a 33rd degree mason:
>On October 19, 1945, Truman was given the 33rd degree of the Supreme Council of the Scottish Rite for the southern jurisdiction. He is the only President to have received this distinction, which he considered with satisfaction to be the culmination of his Masonic career. "Freemasonry," Truman wrote in 1939, "is a system of morals which makes it easier to live with your fellow man, whether he understands it or not." (Letter to Frank P. Briggs, December 13, 1939. Papers as U. S. Senator and Vice President.)
Source: Truman Library
https://www.trumanlibrary.org/places/gv36.htm