4099

This number is a prime.

4099 is the largest known prime such that both distances to the nearest powers of 2 (4096 and 8192) are both prime (3 and 4093). If there is a next prime with that property, it must be greater than 2^3000 (all smaller primes with that property are 11, 13, 19, 29, 61, 67 and 1021). [Vantieghem]