8291

This number is a prime.

8291 is one of the rare primes p for which p^3 = q^3 + r^3 + s^3, where q, r, and s are all primes. 8291^3 = 569928986171 = 2357^3 + 4999^3 + 7559^3. There are only 18 primes like this less than 10000 (709 is the first one). [Keith]