16347...11579 (97-digits)

This number is a prime.

                                               1634733 6458092538 4844313388
3865090859 8417836700 3309231218 1110852389 3331001045 0815121211 8167511579

The smallest prime factor for the RSA challenge number RSA-640. Discovered by F. Bahr, et al., on November 2, 2005. [Sladcik]