Home/Chain Registry/Block #2,682,864

Block #2,682,864

1CCLength 12★★★★☆

Cunningham Chain of the First Kind · Discovered 5/29/2018, 10:15:25 AM · Difficulty 11.6907 · 4,160,380 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
2a06fa594e9ce721bbd5827f205e3cbe069e5dc10c8c185a8e20f10f41fe37c8

Difficulty

11.690666

Transactions

19

Size

6.12 KB

Version

2

Bits

0bb0cf83

Nonce

272,423,881

Timestamp

5/29/2018, 10:15:25 AM

Confirmations

4,160,380

Merkle Root

95d77685730078d80af53060b8d2df45bca8a9adf7ff2168545d21edabdfd662
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.

6.495 × 10⁹⁶(97-digit number)
64954469129050035643…76787743591074887680
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
6.495 × 10⁹⁶(97-digit number)
64954469129050035643…76787743591074887679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.299 × 10⁹⁷(98-digit number)
12990893825810007128…53575487182149775359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.598 × 10⁹⁷(98-digit number)
25981787651620014257…07150974364299550719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.196 × 10⁹⁷(98-digit number)
51963575303240028514…14301948728599101439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.039 × 10⁹⁸(99-digit number)
10392715060648005702…28603897457198202879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.078 × 10⁹⁸(99-digit number)
20785430121296011405…57207794914396405759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.157 × 10⁹⁸(99-digit number)
41570860242592022811…14415589828792811519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.314 × 10⁹⁸(99-digit number)
83141720485184045623…28831179657585623039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.662 × 10⁹⁹(100-digit number)
16628344097036809124…57662359315171246079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.325 × 10⁹⁹(100-digit number)
33256688194073618249…15324718630342492159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
6.651 × 10⁹⁹(100-digit number)
66513376388147236499…30649437260684984319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
12
2^11 × origin − 1
1.330 × 10¹⁰⁰(101-digit number)
13302675277629447299…61298874521369968639
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 12 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
ExceptionalChain length 12
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 2682864

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 2a06fa594e9ce721bbd5827f205e3cbe069e5dc10c8c185a8e20f10f41fe37c8

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 #2,682,864 on Chainz ↗
Circulating Supply:57,990,327 XPM·at block #6,843,243 · updates every 60s
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