XPM Prime Explorer symbol
XPMPrime Explorer
Home/Chain Registry/Block #1,924,666

Block #1,924,666

2CCLength 10β˜…β˜…β˜†β˜†β˜†

Cunningham Chain of the Second Kind Β· Discovered 1/5/2017, 7:22:46 AM Β· Difficulty 10.7220 Β· 4,901,475 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
2c50d1c6a15d3d5fc251d492376a82d130b84e69a0ad28e44bcfa547f4b2e8fa
View on Chainz β†—

Difficulty

10.722011

Transactions

1

Size

199 B

Version

2

Bits

0ab8d5b4

Nonce

988,501,815

Timestamp

1/5/2017, 7:22:46 AM

Confirmations

4,901,475

Merkle Root

ad20be90e79f698ef7b4a8e5d2540bb17f4a791b1df6a64e94119fd93f57ccda
Transactions (1)
Coinbasead20be90e79f69…119fd93f57ccda
1 in β†’ 1 out8.6800 XPM109 B
ASCUQekC…G4MN2EEi
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.

9.571 Γ— 10⁹³(94-digit number)
95713432701413956299…78778371157380671200
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
9.571 Γ— 10⁹³(94-digit number)
95713432701413956299…78778371157380671201
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
2
2^1 Γ— origin + 1
1.914 Γ— 10⁹⁴(95-digit number)
19142686540282791259…57556742314761342401
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
3
2^2 Γ— origin + 1
3.828 Γ— 10⁹⁴(95-digit number)
38285373080565582519…15113484629522684801
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
4
2^3 Γ— origin + 1
7.657 Γ— 10⁹⁴(95-digit number)
76570746161131165039…30226969259045369601
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
5
2^4 Γ— origin + 1
1.531 Γ— 10⁹⁡(96-digit number)
15314149232226233007…60453938518090739201
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
6
2^5 Γ— origin + 1
3.062 Γ— 10⁹⁡(96-digit number)
30628298464452466015…20907877036181478401
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
7
2^6 Γ— origin + 1
6.125 Γ— 10⁹⁡(96-digit number)
61256596928904932031…41815754072362956801
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
8
2^7 Γ— origin + 1
1.225 Γ— 10⁹⁢(97-digit number)
12251319385780986406…83631508144725913601
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
9
2^8 Γ— origin + 1
2.450 Γ— 10⁹⁢(97-digit number)
24502638771561972812…67263016289451827201
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
10
2^9 Γ— origin + 1
4.900 Γ— 10⁹⁢(97-digit number)
49005277543123945625…34526032578903654401
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 1924666

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 2c50d1c6a15d3d5fc251d492376a82d130b84e69a0ad28e44bcfa547f4b2e8fa

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 #1,924,666 on Chainz β†—
Circulating Supply:57,853,254 XPMΒ·at block #6,826,140 Β· updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.
Privacy PolicyΒ·
AQZeJoQ81VgeHQBpEYTgvNqV1gnz3L5SvK

Cookie Preferences

We use cookies to enhance your experience. Some are essential for the site to function, while others help us understand how you use the site.

Β·Privacy Policy