N=(661^4363-1)/660

Portion of N-1 factored: 33.6%
Portion used in proof: 33.366%

Factorization of N-1:
661 = 661
phi_2 = 2 * 331
phi_3 = 3 * 145861
phi_6 = 7 * 62323
phi_727 = 1225723 * 16283347 * c2035
phi_1454 = 2909 * c2045
phi_2181 = 266083 * c4090
phi_4362 = 4363 * p4092