2+(odd)

2^1397+1

Open composite · C296

NFS Planning

GNFS Murphy estimate: 1.52e-20
SNFS Murphy score: 4.04e-19
Preferred method: SNFS
SNFS possible: Yes
SNFS degree: 7
SNFS skew: 1.71875

Identifiers

Target expression: 2^1397+1
Target link: FactorDB page
Target ID: 1000000000012151421
Target changed: -
Parent query: Same as target
Parent ID: -
Cofactor token: C296
Imported: Jun 03, 2026, 04:29 PM UTC

Raw pmain126 Factorization

(1,11,127) 38314813592677405354365631291375300139.33276105604005889302938997033988500026041898371.C296

SNFS Polynomial

Polynomial

Degree: 7
Murphy: 4.04e-19
Skew: 1.71875
Selected: Best

n: 23343962596705395594675165351388913451656122078581731352785029877568532382157468795301380638387665854515503475608285281711070980453857154779635786344175274886966814353990888140850431345867939084618820408947021207113334962020054132304511901951991252574847488340299162545112717670203437098574377731
# 2^1397+1, difficulty: 421.44, skewness: 1.35
# cost: 5.4176e+23, est. time: 257980774.12 GHz days (not accurate yet!)
# Optimized skew: 1.71875 Murphy: 4.04e-19
skew: 1.71875
c7: 1
c0: 8
Y1: -1
Y0: 1606938044258990275541962092341162602522202993782792835301376
type: snfs