Home/Chain Registry/Block #2,649,010

Block #2,649,010

1CCLength 12ā˜…ā˜…ā˜…ā˜…ā˜†

Cunningham Chain of the First Kind Ā· Discovered 5/4/2018, 10:33:05 PM Ā· Difficulty 11.7652 Ā· 4,189,290 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
0375f2ef5743b683e00f2dac78f4bb3fc5c2f943602e82b8dc48c1cf1abc7f24

Difficulty

11.765216

Transactions

4

Size

1.26 KB

Version

2

Bits

0bc3e52b

Nonce

161,746,759

Timestamp

5/4/2018, 10:33:05 PM

Confirmations

4,189,290

Merkle Root

6089087d08e491218334f84ce8800fab4ee55444ef0f9a3e07aecb9ae37ea0a7
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.

1.247 Ɨ 10⁹⁵(96-digit number)
12473530384939401395…84105086618577234560
Discovered Prime Numbers
p_k = 2^k Ɨ origin āˆ’ 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 āˆ’ 1
1.247 Ɨ 10⁹⁵(96-digit number)
12473530384939401395…84105086618577234559
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
2
2^1 Ɨ origin āˆ’ 1
2.494 Ɨ 10⁹⁵(96-digit number)
24947060769878802791…68210173237154469119
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
3
2^2 Ɨ origin āˆ’ 1
4.989 Ɨ 10⁹⁵(96-digit number)
49894121539757605582…36420346474308938239
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
4
2^3 Ɨ origin āˆ’ 1
9.978 Ɨ 10⁹⁵(96-digit number)
99788243079515211164…72840692948617876479
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
5
2^4 Ɨ origin āˆ’ 1
1.995 Ɨ 10⁹⁶(97-digit number)
19957648615903042232…45681385897235752959
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
6
2^5 Ɨ origin āˆ’ 1
3.991 Ɨ 10⁹⁶(97-digit number)
39915297231806084465…91362771794471505919
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
7
2^6 Ɨ origin āˆ’ 1
7.983 Ɨ 10⁹⁶(97-digit number)
79830594463612168931…82725543588943011839
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
8
2^7 Ɨ origin āˆ’ 1
1.596 Ɨ 10⁹⁷(98-digit number)
15966118892722433786…65451087177886023679
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
9
2^8 Ɨ origin āˆ’ 1
3.193 Ɨ 10⁹⁷(98-digit number)
31932237785444867572…30902174355772047359
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
10
2^9 Ɨ origin āˆ’ 1
6.386 Ɨ 10⁹⁷(98-digit number)
63864475570889735145…61804348711544094719
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
11
2^10 Ɨ origin āˆ’ 1
1.277 Ɨ 10⁹⁸(99-digit number)
12772895114177947029…23608697423088189439
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
12
2^11 Ɨ origin āˆ’ 1
2.554 Ɨ 10⁹⁸(99-digit number)
25545790228355894058…47217394846176378879
Verify on FactorDB ↗Wolfram Alpha ↗

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 — 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 →
ā˜…ā˜…ā˜…ā˜…ā˜†
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 Ɨ 3 Ɨ 5 Ɨ 7 Ɨ …), 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 Ɨ Primorial (2Ā·3Ā·5Ā·7Ā·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 1CC formula:

1CC: p₁ (first prime), pā‚‚ = 2p₁ + 1, pā‚ƒ = 2pā‚‚ + 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 2649010

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 0375f2ef5743b683e00f2dac78f4bb3fc5c2f943602e82b8dc48c1cf1abc7f24

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 #2,649,010 on Chainz ↗
Circulating Supply:57,950,676 XPMĀ·at block #6,838,299 Ā· updates every 60s
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