Home/Chain Registry/Block #2,696,197

Block #2,696,197

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 6/7/2018, 10:00:09 PM · Difficulty 11.6701 · 4,147,268 confirmations

1CC
Cunningham Chain of the First Kind

A sequence where each prime is double the previous prime plus one.

Block Header
Block Hash
06daa20def7b8d09c81b99204f81c5ab5f21f3b21cb3e89ad440883f0169c770

Difficulty

11.670083

Transactions

39

Size

8.73 KB

Version

2

Bits

0bab8a97

Nonce

484,873,157

Timestamp

6/7/2018, 10:00:09 PM

Confirmations

4,147,268

Merkle Root

5bda7ae1995d4161a1073765391753e9e09e176aaa7f2c891d7d3811d1cda1c1
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) — it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

1.070 × 10⁹⁸(99-digit number)
10708282714082010109…22720902634974412800
Discovered Prime Numbers
p_k = 2^k × origin − 1

These are the actual prime numbers discovered by this block, computed using the verified Primecoin formula. Each number has been independently confirmed to pass the Fermat primality test. Use the FactorDB links to verify any number independently.

1
origin − 1
1.070 × 10⁹⁸(99-digit number)
10708282714082010109…22720902634974412799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.141 × 10⁹⁸(99-digit number)
21416565428164020218…45441805269948825599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.283 × 10⁹⁸(99-digit number)
42833130856328040436…90883610539897651199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
8.566 × 10⁹⁸(99-digit number)
85666261712656080873…81767221079795302399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.713 × 10⁹⁹(100-digit number)
17133252342531216174…63534442159590604799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.426 × 10⁹⁹(100-digit number)
34266504685062432349…27068884319181209599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.853 × 10⁹⁹(100-digit number)
68533009370124864698…54137768638362419199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.370 × 10¹⁰⁰(101-digit number)
13706601874024972939…08275537276724838399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.741 × 10¹⁰⁰(101-digit number)
27413203748049945879…16551074553449676799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
5.482 × 10¹⁰⁰(101-digit number)
54826407496099891758…33102149106899353599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
1.096 × 10¹⁰¹(102-digit number)
10965281499219978351…66204298213798707199
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 consecutive prime numbers forming a Cunningham Chain of the First Kind. The prime chain origin — the large number shown above — anchors the chain and is divisible by a primorial (the product of small primes), cryptographically tying these prime numbers to this specific block.

View full Prime Chain Discovery page →
★★★☆☆
Rarity
RareChain length 11
How Primecoin's Proof-of-Work Constructs These Primes

Primecoin stores a value called the prime chain origin in each block. The miner found a large integer such that when divided by a primorial (the product of small primes: 2 × 3 × 5 × 7 × …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial — that divisibility is part of the proof.

Prime Chain Origin = First Prime × Primorial (2·3·5·7·11·…)
Source: Primecoin prime.cpp — CheckPrimeProofOfWork()

This is why the origin has many small prime factors — those factors are the primorial divisor. The chain then extends from the first prime using the 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Verify on a Primecoin Node

Anyone running a Primecoin node can independently verify this block using the following RPC commands. Run these from the primecoin-cli command line or via the debug console in the Primecoin wallet.

1. Get block hash by height
getblockhash 2696197

Returns the block hash for a given block height. Use this to confirm the hash shown above matches the chain.

2. Get full block data
getblock 06daa20def7b8d09c81b99204f81c5ab5f21f3b21cb3e89ad440883f0169c770

Returns the full block header including difficulty, prime chain origin, prime chain type, transaction IDs, and all other fields shown on this page.

How to run these commands: To verify this data independently, open a terminal on your own Primecoin node and run primecoin-cli <command>. Alternatively, open the Primecoin-Qt wallet, go to Help → Debug Window → Console, and type the command directly. The node must be fully synced to this block height for the commands to return results.

Cross-reference on Chainz Explorer

Chainz is an independent Primecoin block explorer. Compare this block's data to verify accuracy.

View Block #2,696,197 on Chainz ↗
Circulating Supply:57,992,089 XPM·at block #6,843,464 · updates every 60s
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