14

This number is a composite.

Just showing those entries submitted by 'Firoozbakht': (Click here to show all)

14 = π(1*4) * prime(1*4). Note that 14 is the smallest number with this property. [Firoozbakht]

1!*2!*3!*4!*5!*6!*7!*8!*9!*10!*11!*12!*13!*14! + prime(14) is prime. [Firoozbakht]

14 = prime(1*4) + sigma(1*4). [Firoozbakht]

Prime(14)^14 - π(14) is prime. It is curious that the digits of 14 have the same property. [Firoozbakht]