1657

This number is a prime.

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

1657 = prime( (1*6*5*7) + (1+6+5+7) ) + (1*6*5*7). Note that the prime 1657 is the only number less than 10^7 with this property. [Firoozbakht]