11111...99999 (2316-digits)

This number is a probable-prime (likely to be a prime but we have not (re-)proven it on this site).

Jason Earls’s concrete prime poem, “Lighght Prime” is based on Aram Saroyan’s poem, “Lighght.” (The history of this poem, which engendered considerable controversy when it was first published, is worth looking up.) [Glaz]