• 17 can be written using four 4's:
• McGuire, Tugemann & Civario proved in 2012 that 17 is the minimum possible number of givens for a Sudoku puzzle with unique solution.
• G. Szekeres & L. Peters proved that given 17 points in general position, there are always six of them at the corners of a convex hexagon.
17 is nontrivially palindromic in base 2, base 4 and base 16.
17 is an esthetic number in base 4, base 5, base 7, base 8 and base 15, because in such bases its adjacent digits differ by 1.
It is a strong prime.
17 is a truncatable prime.
It is a cyclic number.
It is a Chen prime.
It is a Leyland number of the form 32 + 23.
It is a hungry number.
17 is an undulating number in base 4.
It is the 10-th Perrin number.
17 is a nontrivial repdigit in base 16.
It is a plaindrome in base 3, base 6, base 7, base 9, base 10, base 11, base 12, base 13, base 14, base 15 and base 16.
It is a nialpdrome in base 5, base 8 and base 16.
It is a zygodrome in base 16.
Being equal to 2×32-1, it is a generalized Woodall number.
It is a good prime.
It is a Pierpont prime, being equal to 24 ⋅ 30 + 1.
A polygon with 17 sides can be constructed with ruler and compass.
It is an amenable number.
17 is an equidigital number, since it uses as much as digits as its factorization.
17 is an evil number, because the sum of its binary digits is even.
The square root of 17 is about 4.1231056256. The cubic root of 17 is about 2.5712815907.
Adding to 17 its reverse (71), we get a palindrome (88).