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Home/Chain Registry/Block #844,939

Block #844,939

2CCLength 10β˜…β˜…β˜†β˜†β˜†

Cunningham Chain of the Second Kind Β· Discovered 12/8/2014, 12:30:24 PM Β· Difficulty 10.9727 Β· 5,997,638 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
4bb3bcc19fcd0f3f464acfb9475ce9e3a8a70471f21bb77919bd68d6a03b4318
View on Chainz β†—

Height

#844,939

Difficulty

10.972656

Transactions

3

Size

657 B

Version

2

Bits

0af8fffb

Nonce

1,537,598,063

Timestamp

12/8/2014, 12:30:24 PM

Confirmations

5,997,638

Merkle Root

a4ec648c20597be3ffe303517297a386aa89b1876c27563caba2fea730a139f3
Transactions (3)
Coinbasebbf67ed7c3c651…3566de2fa8e983
1 in β†’ 1 out8.3100 XPM116 B
ANSXnLY2…Sd25TjkD
d6319037977cf1…ea784d7f7ffe26
1 in β†’ 2 out5.2847 XPM226 B
AXZLdGp1…4dBENGj1AVbLxVJb…PRg27irr
495d530e44f834…dc7df98632c411
1 in β†’ 2 out3.7367 XPM225 B
ASx9RPHT…8fVzc2EyAN5Wwko6…sj5sZnA5
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.

2.543 Γ— 10⁹⁡(96-digit number)
25435208808248120786…07063400213936140640
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
2.543 Γ— 10⁹⁡(96-digit number)
25435208808248120786…07063400213936140641
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
2
2^1 Γ— origin + 1
5.087 Γ— 10⁹⁡(96-digit number)
50870417616496241572…14126800427872281281
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
3
2^2 Γ— origin + 1
1.017 Γ— 10⁹⁢(97-digit number)
10174083523299248314…28253600855744562561
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
4
2^3 Γ— origin + 1
2.034 Γ— 10⁹⁢(97-digit number)
20348167046598496628…56507201711489125121
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
5
2^4 Γ— origin + 1
4.069 Γ— 10⁹⁢(97-digit number)
40696334093196993257…13014403422978250241
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
6
2^5 Γ— origin + 1
8.139 Γ— 10⁹⁢(97-digit number)
81392668186393986515…26028806845956500481
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
7
2^6 Γ— origin + 1
1.627 Γ— 10⁹⁷(98-digit number)
16278533637278797303…52057613691913000961
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
8
2^7 Γ— origin + 1
3.255 Γ— 10⁹⁷(98-digit number)
32557067274557594606…04115227383826001921
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
9
2^8 Γ— origin + 1
6.511 Γ— 10⁹⁷(98-digit number)
65114134549115189212…08230454767652003841
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
10
2^9 Γ— origin + 1
1.302 Γ— 10⁹⁸(99-digit number)
13022826909823037842…16460909535304007681
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 844939

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 4bb3bcc19fcd0f3f464acfb9475ce9e3a8a70471f21bb77919bd68d6a03b4318

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 #844,939 on Chainz β†—
Circulating Supply:57,985,044 XPMΒ·at block #6,842,576 Β· updates every 60s
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