247

247 = 13 x 19. Its digits sum to the smallest prime factor: 2 + 4 + 7 = 13.

247 is a pentagonal number.

247 is the smallest possible difference between two integers that together contain each digit exactly once: 247 = 50,123 - 49876.

247² is one of six square numbers that use the same digits: 247² = 61,009; 130² = 16.900; 140² = 19,600; 310² = 96,100; 103² = 10,609; and 301² = 90,601.

247 Eukrate is a large, dark asteroid discovered in 1885.

Source: Prime Curios!