Home/Chain Registry/Block #2,847,269

Block #2,847,269

1CCLength 12β˜…β˜…β˜…β˜…β˜†

Cunningham Chain of the First Kind Β· Discovered 9/20/2018, 3:29:41 AM Β· Difficulty 11.7328 Β· 3,993,052 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
214523ff57907403bb7fc81fd9d729e6c6f76fba8031962399a3bbb549963577

Difficulty

11.732764

Transactions

1

Size

200 B

Version

2

Bits

0bbb9673

Nonce

38,118,004

Timestamp

9/20/2018, 3:29:41 AM

Confirmations

3,993,052

Merkle Root

afefb6a105a8d58d0bd57963f7eb014dfeb99c158a232b5ab6bc0121caec1eb0
Transactions (1)
1 in β†’ 1 out7.2500 XPM109 B
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.

2.074 Γ— 10⁹⁷(98-digit number)
20741269880313203664…09694920652443832320
Discovered Prime Numbers
p_k = 2^k Γ— origin βˆ’ 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 βˆ’ 1
2.074 Γ— 10⁹⁷(98-digit number)
20741269880313203664…09694920652443832319
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
2
2^1 Γ— origin βˆ’ 1
4.148 Γ— 10⁹⁷(98-digit number)
41482539760626407329…19389841304887664639
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
3
2^2 Γ— origin βˆ’ 1
8.296 Γ— 10⁹⁷(98-digit number)
82965079521252814659…38779682609775329279
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
4
2^3 Γ— origin βˆ’ 1
1.659 Γ— 10⁹⁸(99-digit number)
16593015904250562931…77559365219550658559
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
5
2^4 Γ— origin βˆ’ 1
3.318 Γ— 10⁹⁸(99-digit number)
33186031808501125863…55118730439101317119
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
6
2^5 Γ— origin βˆ’ 1
6.637 Γ— 10⁹⁸(99-digit number)
66372063617002251727…10237460878202634239
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
7
2^6 Γ— origin βˆ’ 1
1.327 Γ— 10⁹⁹(100-digit number)
13274412723400450345…20474921756405268479
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
8
2^7 Γ— origin βˆ’ 1
2.654 Γ— 10⁹⁹(100-digit number)
26548825446800900690…40949843512810536959
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
9
2^8 Γ— origin βˆ’ 1
5.309 Γ— 10⁹⁹(100-digit number)
53097650893601801381…81899687025621073919
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
10
2^9 Γ— origin βˆ’ 1
1.061 Γ— 10¹⁰⁰(101-digit number)
10619530178720360276…63799374051242147839
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
11
2^10 Γ— origin βˆ’ 1
2.123 Γ— 10¹⁰⁰(101-digit number)
21239060357440720552…27598748102484295679
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
12
2^11 Γ— origin βˆ’ 1
4.247 Γ— 10¹⁰⁰(101-digit number)
42478120714881441105…55197496204968591359
Verify on FactorDB β†—Wolfram Alpha β†—

What this block proved

The miner who found this block proved the existence of 12 consecutive prime numbers forming a Cunningham Chain of the First 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
ExceptionalChain length 12
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 1CC formula:

1CC: p₁ (first prime), pβ‚‚ = 2p₁ + 1, p₃ = 2pβ‚‚ + 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 2847269

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 214523ff57907403bb7fc81fd9d729e6c6f76fba8031962399a3bbb549963577

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 #2,847,269 on Chainz β†—
Circulating Supply:57,966,888 XPMΒ·at block #6,840,320 Β· updates every 60s
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