The composite cofactor of F1839 was the product of 66-digit, 90-digit, and 98-digit prime numbers:

66-digit prime factor:
399817149624898537988769186259393023387862615763326417749602163949

90-digit prime factor:
369185495724920841192300764747253650798550984366430546957456311598498423383631698219246109

98-digit prime factor:
15248154080868465435734407208305846536742964243204353023035616128605935278133744710563734776997653

The factors have been reported to the Fibonacci project.