250431285

This number is a composite.

250431285 * 2³⁵⁵⁷ - 1 is both a titanic twin prime and a titanic Sophie Germain prime, since 250431285 * 2³⁵⁵⁷ + 1 and 250431285 * 2³⁵⁵⁸ - 1 are prime. [Broadhurst]