2+(odd)

2^1261+1

Open composite · C302

NFS Planning

GNFS Murphy estimate: 6.80e-21
SNFS Murphy score: 4.15e-17
Preferred method: SNFS
SNFS possible: Yes
SNFS degree: 6
SNFS skew: 1.41528

Identifiers

Target expression: 2^1261+1
Target link: FactorDB page
Target ID: 1000000000012151285
Target changed: -
Parent query: Same as target
Parent ID: -
Cofactor token: C302
Imported: Jun 03, 2026, 04:29 PM UTC

Raw pmain126 Factorization

(1,13,97) 25571706135457.73763414723376088026310008245531. C302

SNFS Polynomial

Polynomial

Degree: 6
Murphy: 4.15e-17
Skew: 1.41528
Selected: Best

n: 48639884444240084908770017756667200783693803645156519086773540460599299617013287083827771511312703767125525131278271974550158780384175260009227073697672567825658934020729168813007484865081942484402036785878963886987310276022316221764969369206167569758250409384811983670095938887597537995444358240855193
# 2^1261+1, difficulty: 350.40, skewness: 1.00
# cost: 8.24464e+21, est. time: 3926019.06 GHz days (not accurate yet!)
# Optimized skew: 1.41528 Murphy: 4.15e-17
skew: 1.41528
c6: 1
c5: -1
c4: -5
c3: 4
c2: 6
c1: -3
c0: -1
Y1: -158456325028528675187087900672
Y0: 25108406941546723055343157692830665664409421777856138051585
type: snfs