This number is a composite.
The smallest semiprime and brilliant number which is prime
when reversed and when turned upside down. [Capelle]
The smallest 4-digit brilliant number, (1081 = 23 x 47),
whose the concatenations of prime factors are both primes,
i.e., 2347, 4723. [Loungrides]
Printed from the PrimePages <t5k.org> © G. L. Honaker and Chris K. Caldwell