2^1291-1

Open composite · C348

NFS Planning

GNFS Murphy estimate: 1.46e-23
SNFS Murphy score: 5.16e-18
Preferred method: SNFS
SNFS possible: Yes
SNFS degree: 7
SNFS skew: 1.06071

Identifiers

Target expression: 2^1291-1
Target link: FactorDB page
Target ID: 1000000000000001291
Target changed: -
Parent query: Same as target
Parent ID: -
Cofactor token: C348
Imported: Jun 03, 2026, 04:29 PM UTC

Raw pmain126 Factorization

998943080897.84051400422953302189544581841. C348

SNFS Polynomial

Polynomial

Degree: 7
Murphy: 5.16e-18
Skew: 1.06071
Selected: Best

n: 507736874452002837648237105085992460558920864245347321121785658577291793148853021122006108973548047934636978340969385500509617912366199657211552047807792170722217220122287577656519118000014685363397910534787524264443539745595949627559472949877798290802507465416930892721053618332712512729695099113218711914719636030068832375052363183763347920000911
# 2^1291-1, difficulty: 388.63, skewness: 1.35
# cost: 8.30393e+22, est. time: 39542537.22 GHz days (not accurate yet!)
# Optimized skew: 1.06071 Murphy: 5.16e-18
skew: 1.06071
c7: 1
c0: -8
Y1: -24519928653854221733733552434404946937899825954937634816
Y0: 1
type: snfs