2+(odd)

2^1291+1

Open composite · C284

NFS Planning

GNFS Murphy estimate: 7.53e-20
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: 1000000000012151315
Target changed: -
Parent query: Same as target
Parent ID: -
Cofactor token: C284
Imported: Jun 03, 2026, 04:29 PM UTC

Raw pmain126 Factorization

(1) 28403.16981242584548819.40397701481598169.20160790854725168608079143216009.2028519999628439233287004349186690347.C284

SNFS Polynomial

Polynomial

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

n: 17833063405672968730973714123132888122789040355906969718361290403263745085918958969349087086910521674729521302019242086266563472445640842863452044505607778551676665906936220296551655018366085231375182915989705722630691235215199883678361342457943681995452565571733831027006265326741337
# 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