P · Proven prime
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.
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Term #1 of the Home prime · Base 6 sequence of
2238
Term #1 of the Inverse home prime · Base 5 sequence of
6851
Term #1 of the Inverse home prime · Base 11 sequence of
3602
Term #2 of the Home prime · Base 21 sequence of
939
Term #1 of the Aliquot variants · Augmented · σ(n) − n + 1 sequence of
10764
Term #1 of the Inverse home prime · Base 14 sequence of
1717
Term #1 of the Inverse home prime · Base 25 sequence of
6851
Term #1 of the Inverse home prime · Base 32 sequence of
1045
Term #1 of the Conway climb · Base 6 sequence of
2238
Term #1 of the Conway climb · Base 14 sequence of
5831
Term #1 of the Conway climb · Base 18 sequence of
1911
Term #2 of the Conway climb · Base 21 sequence of
939
Term #5 of the Second-class home prime · Base 10 sequence of
224
Term #1 of the Mid-divisor concatenation · Base 2 sequence of
12429
Term #2 of the Mid-divisor concatenation · Base 16 sequence of
2910
Is factor of
Primality
Verified directlyproven prime
Checked deterministically (below 300 digits).
From the command linefdb · curl
fdb
fdb number '19813' --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":{"expr":"19813"},"decimal":false,"detail":2}}'