Because it has more than two factors.
The Prime Factor of 289 is 17
No - The prime factors of 289 are 17 and 17.
1, 17, 289 17 is prime.
The prime number (factor) of 289 is: 17
17*17 = 289
its prime
17 x 17 = 289
17 x 17 = 289
289 17,17
289 = 17^2 17 x 17
289 is composite. 289 = 17 * 17 = 172
17 x 17 = 289