Home/Chain Registry/Block #519,372

Block #519,372

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/1/2014, 4:45:07 AM · Difficulty 10.8559 · 6,276,252 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
2ebc53f7e8a967cf9a83833ce26d6a20c6e792db89b9797937ea0e5d05fe813d

Height

#519,372

Difficulty

10.855912

Transactions

8

Size

1.89 KB

Version

2

Bits

0adb1d0a

Nonce

122,205,375

Timestamp

5/1/2014, 4:45:07 AM

Confirmations

6,276,252

Merkle Root

4f2aa7d9107408b7019e2f21f3f81e92baea70b0895e49ef60f65478e1420656
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.

2.453 × 10⁹⁹(100-digit number)
24537663422354833235…23973299527310169600
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
2.453 × 10⁹⁹(100-digit number)
24537663422354833235…23973299527310169601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
4.907 × 10⁹⁹(100-digit number)
49075326844709666471…47946599054620339201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
9.815 × 10⁹⁹(100-digit number)
98150653689419332943…95893198109240678401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.963 × 10¹⁰⁰(101-digit number)
19630130737883866588…91786396218481356801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
3.926 × 10¹⁰⁰(101-digit number)
39260261475767733177…83572792436962713601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
7.852 × 10¹⁰⁰(101-digit number)
78520522951535466354…67145584873925427201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.570 × 10¹⁰¹(102-digit number)
15704104590307093270…34291169747850854401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.140 × 10¹⁰¹(102-digit number)
31408209180614186541…68582339495701708801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
6.281 × 10¹⁰¹(102-digit number)
62816418361228373083…37164678991403417601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.256 × 10¹⁰²(103-digit number)
12563283672245674616…74329357982806835201
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 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
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 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 519372

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 2ebc53f7e8a967cf9a83833ce26d6a20c6e792db89b9797937ea0e5d05fe813d

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 #519,372 on Chainz ↗
Circulating Supply:57,609,059 XPM·at block #6,795,623 · updates every 60s
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