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 aliquot sequence of
513125
Term #3 of the Home prime · Base 2 sequence of
7038
Term #1 of the Home prime · Base 4 sequence of
77987
Term #1 of the Home prime · Base 8 sequence of
91659
Term #2 of the Inverse home prime · Base 4 sequence of
9933
Term #1 of the Inverse home prime · Base 5 sequence of
8323
Term #1 of the Home prime · Base 24 sequence of
91207
Term #2 of the Home prime · Base 32 sequence of
46547
Term #1 of the Aliquot variants · Augmented · σ(n) − n + 1 sequence of
74184
Term #1 of the Inverse home prime · Base 16 sequence of
44767
Term #1 of the Inverse home prime · Base 18 sequence of
90913
Term #1 of the Inverse home prime · Base 22 sequence of
17571
Term #3 of the Conway climb · Base 2 sequence of
9384
Term #1 of the Conway climb · Base 4 sequence of
77987
Term #1 of the Conway climb · Base 6 sequence of
71056
Term #1 of the Conway climb · Base 8 sequence of
91659
Term #2 of the Conway climb · Base 15 sequence of
10551
Term #1 of the Conway climb · Base 24 sequence of
91207
Term #2 of the Conway climb · Base 32 sequence of
46547
Term #4 of the Distinct-prime home prime · Base 2 sequence of
9690
Term #1 of the Distinct-prime home prime · Base 8 sequence of
91659
Term #1 of the Distinct-prime home prime, descending · Base 16 sequence of
44767
Term #1 of the Second-class home prime · Base 2 sequence of
77130
Term #2 of the Second-class home prime · Base 8 sequence of
72780
Term #4 of the Mid-divisor concatenation · Base 2 sequence of
23886
Term #5 of the Mid-divisor concatenation · Base 3 sequence of
21706
Term #3 of the Mid-divisor concatenation · Base 8 sequence of
10988
Is factor of
Primality
Verified directlyproven prime
Checked deterministically (below 300 digits).
From the command linefdb · curl
fdb
fdb number '128857' --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":"128857"},"decimal":false,"detail":2}}'