150

This number is a composite.

2¹⁵⁰ - 3 and 2¹⁵⁰ - 5 are twin primes. [Kulsha]

150 is the largest gap between consecutive twin prime pairs less than a thousand. It occurs between {659, 661} and {809, 811}. [Opao]

Smallest base such where there is a known titanic generalized Fermat prime. [Xayah]