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Home/Chain Registry/Block #6,784,919

Block #6,784,919

2CCLength 10β˜…β˜…β˜†β˜†β˜†

Cunningham Chain of the Second Kind Β· Discovered 4/5/2026, 10:41:42 PM Β· Difficulty 10.9809 Β· 10,518 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
d2410a9a8b2fcf59e0edc8f67074d37f04ed57070d9476e80dc82fa8cbaa6cf5
View on Chainz β†—

Difficulty

10.980864

Transactions

1

Size

191 B

Version

536870912

Bits

0afb19e9

Nonce

2,137,383,028

Timestamp

4/5/2026, 10:41:42 PM

Confirmations

10,518

Merkle Root

0223fafa80bd36fd49fc70499854bd3c9cb4e0fd64335191085597958ece185f
Transactions (1)
Coinbase0223fafa80bd36…5597958ece185f
1 in β†’ 1 out8.1790 XPM101 B
AMrLYUQN…jwjifxiz
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) β€” it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

2.270 Γ— 10⁹⁡(96-digit number)
22709851531478391717…13935492910390165600
Discovered Prime Numbers
p_k = 2^k Γ— 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
2.270 Γ— 10⁹⁡(96-digit number)
22709851531478391717…13935492910390165601
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
2
2^1 Γ— origin + 1
4.541 Γ— 10⁹⁡(96-digit number)
45419703062956783434…27870985820780331201
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
3
2^2 Γ— origin + 1
9.083 Γ— 10⁹⁡(96-digit number)
90839406125913566868…55741971641560662401
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
4
2^3 Γ— origin + 1
1.816 Γ— 10⁹⁢(97-digit number)
18167881225182713373…11483943283121324801
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
5
2^4 Γ— origin + 1
3.633 Γ— 10⁹⁢(97-digit number)
36335762450365426747…22967886566242649601
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
6
2^5 Γ— origin + 1
7.267 Γ— 10⁹⁢(97-digit number)
72671524900730853494…45935773132485299201
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
7
2^6 Γ— origin + 1
1.453 Γ— 10⁹⁷(98-digit number)
14534304980146170698…91871546264970598401
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
8
2^7 Γ— origin + 1
2.906 Γ— 10⁹⁷(98-digit number)
29068609960292341397…83743092529941196801
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
9
2^8 Γ— origin + 1
5.813 Γ— 10⁹⁷(98-digit number)
58137219920584682795…67486185059882393601
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
10
2^9 Γ— origin + 1
1.162 Γ— 10⁹⁸(99-digit number)
11627443984116936559…34972370119764787201
Verify on FactorDB β†—Wolfram Alpha β†—

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 β€” the large number shown above β€” 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 β†’
β˜…β˜…β˜†β˜†β˜†
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 Γ— 3 Γ— 5 Γ— 7 Γ— …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial β€” that divisibility is part of the proof.

Prime Chain Origin = First Prime Γ— Primorial (2Β·3Β·5Β·7Β·11·…)
Source: Primecoin prime.cpp β€” CheckPrimeProofOfWork()

This is why the origin has many small prime factors β€” those factors are the primorial divisor. The chain then extends from the first prime using the 2CC formula:

2CC: p₁ (first prime), pβ‚‚ = 2p₁ βˆ’ 1, p₃ = 2pβ‚‚ βˆ’ 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 6784919

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 d2410a9a8b2fcf59e0edc8f67074d37f04ed57070d9476e80dc82fa8cbaa6cf5

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 β†’ Debug Window β†’ 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 #6,784,919 on Chainz β†—
Circulating Supply:57,607,559 XPMΒ·at block #6,795,436 Β· updates every 60s
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