Home/Chain Registry/Block #632,421

Block #632,421

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 7/14/2014, 5:05:03 AM · Difficulty 10.9629 · 6,181,656 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
5e3823b471a4824446570dfced3ebf9feae07154a20fd8a0e52b443b84530301

Height

#632,421

Difficulty

10.962938

Transactions

8

Size

2.40 KB

Version

2

Bits

0af6831d

Nonce

88,127,567

Timestamp

7/14/2014, 5:05:03 AM

Confirmations

6,181,656

Merkle Root

7b7d9f59cfae56d6ca04acfe7f23674d1f7140297c145d626ca0a6a9abc6dda9
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.

3.304 × 10⁹⁷(98-digit number)
33044384929969486702…47691815443983308800
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
3.304 × 10⁹⁷(98-digit number)
33044384929969486702…47691815443983308801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.608 × 10⁹⁷(98-digit number)
66088769859938973405…95383630887966617601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.321 × 10⁹⁸(99-digit number)
13217753971987794681…90767261775933235201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.643 × 10⁹⁸(99-digit number)
26435507943975589362…81534523551866470401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.287 × 10⁹⁸(99-digit number)
52871015887951178724…63069047103732940801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.057 × 10⁹⁹(100-digit number)
10574203177590235744…26138094207465881601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.114 × 10⁹⁹(100-digit number)
21148406355180471489…52276188414931763201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.229 × 10⁹⁹(100-digit number)
42296812710360942979…04552376829863526401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
8.459 × 10⁹⁹(100-digit number)
84593625420721885959…09104753659727052801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.691 × 10¹⁰⁰(101-digit number)
16918725084144377191…18209507319454105601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
3.383 × 10¹⁰⁰(101-digit number)
33837450168288754383…36419014638908211201
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 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
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 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 632421

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 5e3823b471a4824446570dfced3ebf9feae07154a20fd8a0e52b443b84530301

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 #632,421 on Chainz ↗
Circulating Supply:57,756,696 XPM·at block #6,814,076 · updates every 60s
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