1747

This number is a prime.

The number of digits in the iterated factorial 3!!!. [Hartley]

The only 4-digit prime that both shares no digits with its square and has the same sum of digits as its square. [Gaydos]

Pluto became closer to the Sun than Neptune in the prime year 1747. [Zhang]

Smallest prime whose prime index (272) is equal to the sum of factors of its reversal: 7471 = 31 x 241. [Sariyar]

The year J. S. Bach visited Frederick the Great in Potsdam, and later sent his Musical Offering as a thank-you note. He arrived there on the prime date of May 7th and published that music on the prime date of July 7th. 1747 contains 17 and 47, which JSB would have noticed. The main theme has 5 + 5 + 11 notes, and appears in measures 47 and 229 of the 2nd movement and measure 23 of the last movement of the sonata. It contains 5 + 5 canons. [Bodine]