2^1265-1

Open composite · C223

NFS Planning

GNFS Murphy estimate: 2.60e-16
SNFS Murphy score: 5.16e-16
Preferred method: Similar
SNFS possible: Yes
SNFS degree: 8
SNFS skew: 0.80277

Identifiers

Target expression: 2^1265-1
Target link: FactorDB page
Target ID: 1000000000000001265
Target changed: -
Parent query: Same as target
Parent ID: -
Cofactor token: C223
Imported: Jun 03, 2026, 04:29 PM UTC

Raw pmain126 Factorization

(5,11,23,55,115,253) 121441.533831.136149590957161.556590676780973231.C223

SNFS Polynomial

Polynomial

Degree: 8
Murphy: 5.16e-16
Skew: 0.80277
Selected: Best

n: 3177637419411999355129944886689559346101861105519571056871246628360895113744933461523914954036024798274195026064378322107880381735190532079548937856627214380238040726924600192728299334751303551461562426661369780723999927471
# 2^1265-1, difficulty: 304.64, skewness: 0.71
# cost: 4.21504e+20, est. time: 200716.36 GHz days (not accurate yet!)
# Optimized skew: 0.80277 Murphy: 5.16e-16
skew: 0.80277
c8: 16
c6: 8
c4: 4
c2: 2
c0: 1
Y1: -1
Y0: 85070591730234615865843651857942052864
type: snfs