Home/Chain Registry/Block #2,038,723

Block #2,038,723

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/26/2017, 1:36:42 AM · Difficulty 10.6808 · 4,803,543 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
9a7d166f1e9a5d39b7912a6599ee785650a48d0c97bd0a629c58a7330fb93bf6

Difficulty

10.680764

Transactions

2

Size

1.14 KB

Version

2

Bits

0aae4691

Nonce

766,363,278

Timestamp

3/26/2017, 1:36:42 AM

Confirmations

4,803,543

Merkle Root

adff6a315e80416ca6a20551da897a1664727a53d43b8738b9d0cff95b52ebc6
Transactions (2)
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.

1.355 × 10⁹⁵(96-digit number)
13558738695223199305…83609039235163897600
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
1.355 × 10⁹⁵(96-digit number)
13558738695223199305…83609039235163897599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.711 × 10⁹⁵(96-digit number)
27117477390446398611…67218078470327795199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.423 × 10⁹⁵(96-digit number)
54234954780892797222…34436156940655590399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.084 × 10⁹⁶(97-digit number)
10846990956178559444…68872313881311180799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.169 × 10⁹⁶(97-digit number)
21693981912357118888…37744627762622361599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.338 × 10⁹⁶(97-digit number)
43387963824714237777…75489255525244723199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
8.677 × 10⁹⁶(97-digit number)
86775927649428475555…50978511050489446399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.735 × 10⁹⁷(98-digit number)
17355185529885695111…01957022100978892799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.471 × 10⁹⁷(98-digit number)
34710371059771390222…03914044201957785599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
6.942 × 10⁹⁷(98-digit number)
69420742119542780444…07828088403915571199
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 2038723

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 9a7d166f1e9a5d39b7912a6599ee785650a48d0c97bd0a629c58a7330fb93bf6

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 #2,038,723 on Chainz ↗
Circulating Supply:57,982,527 XPM·at block #6,842,265 · updates every 60s
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