Home/Chain Registry/Block #2,582,782

Block #2,582,782

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 3/24/2018, 11:08:39 AM · Difficulty 11.1432 · 4,258,298 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
7e7405ffd5ce851b455c700e81dfa90fd9e9cc3382c6ec0205f5ff9009ddb0fb

Difficulty

11.143155

Transactions

9

Size

2.97 KB

Version

2

Bits

0b24a5c6

Nonce

614,769,907

Timestamp

3/24/2018, 11:08:39 AM

Confirmations

4,258,298

Merkle Root

63acdde2aaba169d55d5ffc7e6e8571f55046438c41e5151724899bec055737b
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.

1.857 × 10⁹⁴(95-digit number)
18570175394339733098…55524319229478617280
Discovered Prime Numbers
p_k = 2^k × 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
1.857 × 10⁹⁴(95-digit number)
18570175394339733098…55524319229478617281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.714 × 10⁹⁴(95-digit number)
37140350788679466196…11048638458957234561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
7.428 × 10⁹⁴(95-digit number)
74280701577358932393…22097276917914469121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.485 × 10⁹⁵(96-digit number)
14856140315471786478…44194553835828938241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.971 × 10⁹⁵(96-digit number)
29712280630943572957…88389107671657876481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.942 × 10⁹⁵(96-digit number)
59424561261887145914…76778215343315752961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.188 × 10⁹⁶(97-digit number)
11884912252377429182…53556430686631505921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.376 × 10⁹⁶(97-digit number)
23769824504754858365…07112861373263011841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.753 × 10⁹⁶(97-digit number)
47539649009509716731…14225722746526023681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
9.507 × 10⁹⁶(97-digit number)
95079298019019433463…28451445493052047361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
1.901 × 10⁹⁷(98-digit number)
19015859603803886692…56902890986104094721
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 consecutive prime numbers forming a Cunningham Chain of the Second 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 →
★★★☆☆
Rarity
RareChain length 11
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 × 3 × 5 × 7 × …), 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 × Primorial (2·3·5·7·11·…)
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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 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 2582782

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 7e7405ffd5ce851b455c700e81dfa90fd9e9cc3382c6ec0205f5ff9009ddb0fb

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 #2,582,782 on Chainz ↗
Circulating Supply:57,973,002 XPM·at block #6,841,079 · updates every 60s
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