1027

This number is a composite.

1027 is the smallest number m such that 1000^1000 + m is prime. [Firoozbakht]

This sum of the sum of 7 consecutive primes (131 + 137 + 139 + 149 + 151 + 157 + 163) is also the sum of the squares of the first 8 primes 2^2 + 3^2 + 5^2 + 7^2 + 11^2 + 13^2 + 17^2 + 19^2 and the smallest number which has 9 embedded primes (2, 7, 17, 71, 107, 271, 701, 1027, 2017). It is the closest semiprime to 2^10. Hence it has properties associated with 7=7+0, 8=7+1, 9=7+2, 10=1+0+2+7. [Post]