18885
This number is a composite.
The Woodall prime 18885*2^18885-1 was discovered by Wilfrid Keller in 1987; it was the 43rd largest known prime as of August 1989 according to a list of titanic primes compiled by Samuel Yates. [Dobb]
Printed from the PrimePages <t5k.org> © G. L. Honaker and Chris K. Caldwell