2087

This number is a prime.

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It is curious that the reverse of 2087^9 is prime: 2087^9 = 751107401498753081320863207527: its reverse = 725702368023180357894104701157 is prime.

20^2087 - repeat(2087, 423 times) is prime: this 2716-digit prime ends with repeat(9, 395 times), followed by 791, followed by repeat(2791, 422 times), and ends with 3: also note that 2791 is prime; 30^2087 - repeat(2087, 461 times) is prime: this 3083 digit prime ends with repeat(9, 243 times), followed by 791, followed by repeat(2791, 460 times), and ends with 3: also note that 2791 is prime; 24^2087 + repeat(2087, 509 times) is prime: this is a 2881-digit prime: also note that 509 is prime.

32^2087 - 208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087208720872087 = 2^10435 - repeat(2087, 87 times) is a 3142-digit prime. [Noll]