6868

6868 = 2 x 2 x 17 x 101.

6868 is the larger number in a Ruth-Aaron pair.

6868 is 100102101 in base 3. It is 15234 in base 8 (uses each of the digits from 1 to 5 once).

6868 has two representations as a sum of two squares: 6868 = 12² + 82² = 28² + 78².

6868 divides 91¹⁶ - 1.

Source: What's Special About This Number?