Home/Chain Registry/Block #164,331

Block #164,331

2CCLength 9★☆☆☆☆

Cunningham Chain of the Second Kind · Discovered 9/14/2013, 2:43:20 PM · Difficulty 9.8623 · 6,630,986 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
d083be2c5caac8566c2384fc7d5e48c276d60fd59fbe93a4635a69ac588c04a9

Height

#164,331

Difficulty

9.862258

Transactions

12

Size

3.05 KB

Version

2

Bits

09dcbcec

Nonce

332,824

Timestamp

9/14/2013, 2:43:20 PM

Confirmations

6,630,986

Merkle Root

e7385bf0b80f46b77ffac102f923a4d2154f9d36ee04ae30490d0423f7f39e17
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.

3.616 × 10⁹⁰(91-digit number)
36160920189580789914…10173591444199564720
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
3.616 × 10⁹⁰(91-digit number)
36160920189580789914…10173591444199564721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
7.232 × 10⁹⁰(91-digit number)
72321840379161579829…20347182888399129441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.446 × 10⁹¹(92-digit number)
14464368075832315965…40694365776798258881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.892 × 10⁹¹(92-digit number)
28928736151664631931…81388731553596517761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.785 × 10⁹¹(92-digit number)
57857472303329263863…62777463107193035521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.157 × 10⁹²(93-digit number)
11571494460665852772…25554926214386071041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.314 × 10⁹²(93-digit number)
23142988921331705545…51109852428772142081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.628 × 10⁹²(93-digit number)
46285977842663411091…02219704857544284161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
9.257 × 10⁹²(93-digit number)
92571955685326822182…04439409715088568321
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 consecutive prime numbers forming a Cunningham Chain of the Second 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
CommonChain length 9
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 2CC formula:

2CC: 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 164331

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 d083be2c5caac8566c2384fc7d5e48c276d60fd59fbe93a4635a69ac588c04a9

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 #164,331 on Chainz ↗
Circulating Supply:57,606,591 XPM·at block #6,795,316 · updates every 60s
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