I looked at the generalized Fermat-prime-numbers. According to factordb, the case $$10^{2^{21}}+1$$ is unknown. Neither a factor is displayed nor $C$ for "composite". Hence my question :
Is $$10^{2^{21}}+1$$ be known to be composite ? Is a factor known ? If no, what is the search limit ?
PFGW: $$10^{2^{21}}+1$$ is composite: RES64: [651AE2CA2B659AF9] (175710.6149s+0.0590s)