Home/Chain Registry/Block #2,110,976

Block #2,110,976

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 5/11/2017, 3:10:54 AM · Difficulty 10.9034 · 4,731,147 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
09accbea7a456ad45998fbd45e2ee75e2dad555c0121189b25d39ca947e10024

Difficulty

10.903376

Transactions

3

Size

801 B

Version

2

Bits

0ae743a6

Nonce

489,538,376

Timestamp

5/11/2017, 3:10:54 AM

Confirmations

4,731,147

Merkle Root

495046d10bbdda7ba97e3685f2aab7bc230fa7eefbd3f365cea6dd9b777d934f
Transactions (3)
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.

6.440 × 10⁹⁶(97-digit number)
64402295028330484431…52823008734914969600
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
6.440 × 10⁹⁶(97-digit number)
64402295028330484431…52823008734914969599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.288 × 10⁹⁷(98-digit number)
12880459005666096886…05646017469829939199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.576 × 10⁹⁷(98-digit number)
25760918011332193772…11292034939659878399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.152 × 10⁹⁷(98-digit number)
51521836022664387545…22584069879319756799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.030 × 10⁹⁸(99-digit number)
10304367204532877509…45168139758639513599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.060 × 10⁹⁸(99-digit number)
20608734409065755018…90336279517279027199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.121 × 10⁹⁸(99-digit number)
41217468818131510036…80672559034558054399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.243 × 10⁹⁸(99-digit number)
82434937636263020072…61345118069116108799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.648 × 10⁹⁹(100-digit number)
16486987527252604014…22690236138232217599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.297 × 10⁹⁹(100-digit number)
32973975054505208028…45380472276464435199
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 10 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
UncommonChain length 10
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 2110976

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 09accbea7a456ad45998fbd45e2ee75e2dad555c0121189b25d39ca947e10024

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 #2,110,976 on Chainz ↗
Circulating Supply:57,981,372 XPM·at block #6,842,122 · updates every 60s
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