This number is a composite.
178 = 2 x 89. Note that 2 and 89 are the smallest and the largest Mersenne prime exponents under 100. [Luhn]
The smallest integer with three different digits for which
every permutation of its digits is a semiprime. [Gaydos]
Printed from the PrimePages <primes.utm.edu> © G. L. Honaker and Chris K. Caldwell