factordbrpc · fdb
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Enter a value, an expression, or a term with a variable like 10^n+1 to list a range. Switch to Database id to look a number up by its stored id. Reading never stores anything; use Create to add a number to the database. See the expression syntax & functions reference.

P · Proven prime
id #1000000000043587043 19 digits
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Interesting number. Oscar Hoppe proved this 19-digit repunit prime in 1916 - the first repunit primality proof, decades after Lucas had tabulated periods of 1/p.

Value

1111111111…11<19>
term (10^19-1)/9
1111111111…11<19>
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Is factor of

Primality

Verified directlyproven prime

Checked deterministically (below 300 digits).

From the command linefdb · curl
fdb
fdb number id:1000000000043587043 --detail 2
curl
curl -s 'https://factordb.com:4059/rpc' -H 'Content-Type: application/json' -d '{"jsonrpc":"2.0","id":1,"method":"get_number","params":{"target":{"id":1000000000043587043},"decimal":false,"detail":2}}'