factordb · 2305843009…51<19>

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 #1000000000000000061 19 digits

★

Interesting number. Proved prime by Pervushin in 1883 with Lucas sequences, though Mersenne's 1644 list had omitted it; today a popular modulus for fast 64-bit polynomial hashing.

Value

Base

2305843009213693951

term 2^61-1

2305843009…51<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:1000000000000000061 --detail 2 --decimal

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":1000000000000000061},"decimal":true,"detail":2}}'