2+(4k)

2^1216+1

Open composite · C263

NFS Planning

GNFS Murphy estimate: 1.24e-18
SNFS Murphy score: 2.78e-17
Preferred method: SNFS
SNFS possible: Yes
SNFS degree: 7
SNFS skew: 1.53992

Identifiers

Target expression: 2^1216+1
Target link: FactorDB page
Target ID: 1000000000012151240
Target changed: -
Parent query: Same as target
Parent ID: -
Cofactor token: C263
Imported: Jun 03, 2026, 04:30 PM UTC

Raw pmain126 Factorization

(64) 36713210266033084673.16829646106971151773253785496003719032544890827599795902421932801.C263

SNFS Polynomial

Polynomial

Degree: 7
Murphy: 2.78e-17
Skew: 1.53992
Selected: Best

n: 99005121149331816102456158616084232794913814357859563827831605701354285512707940642990325982491421840844216407234779624485541287559566260933138949017913372134779248537511713386342744587963759060390513535053261848720355308564612983998292411472648724543757382880257
# 2^1216+1, difficulty: 366.65, skewness: 1.22
# cost: 2.24057e+22, est. time: 10669387.91 GHz days (not accurate yet!)
# Optimized skew: 1.53992 Murphy: 2.78e-17
skew: 1.53992
c7: 1
c0: 4
Y1: -1
Y0: 23945242826029513411849172299223580994042798784118784
type: snfs