GMP-ECM 7.0.4-dev [configured with MPIR 2.7.2, --enable-openmp] [ECM] Input number is Phi(16576,10) (6913 digits) Using B1=250000, B2=0, polynomial x^1, sigma=0:6286726152992542352 Step 1 took 500841ms ********** Factor found in step 1: 736806111316855372801 Found probable prime factor of 21 digits: 736806111316855372801 Composite cofactor (Phi(16576,10))/736806111316855372801 has 6892 digits