Home/Chain Registry/Block #882,017

Block #882,017

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/4/2015, 3:40:44 PM · Difficulty 10.9607 · 5,916,888 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
dae798382fc58f5780904283a64953c9674852a1d00dbe6ad2076794059d2b83

Height

#882,017

Difficulty

10.960712

Transactions

10

Size

4.64 KB

Version

2

Bits

0af5f13c

Nonce

167,324,992

Timestamp

1/4/2015, 3:40:44 PM

Confirmations

5,916,888

Merkle Root

9ffa01e2d144816d69bfe013bd50bf783b09ac4dd85519a0db61bf9f8767ba1c
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.

2.054 × 10⁹⁷(98-digit number)
20545413612425768385…70221145635090385920
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
2.054 × 10⁹⁷(98-digit number)
20545413612425768385…70221145635090385921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
4.109 × 10⁹⁷(98-digit number)
41090827224851536770…40442291270180771841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
8.218 × 10⁹⁷(98-digit number)
82181654449703073541…80884582540361543681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.643 × 10⁹⁸(99-digit number)
16436330889940614708…61769165080723087361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
3.287 × 10⁹⁸(99-digit number)
32872661779881229416…23538330161446174721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
6.574 × 10⁹⁸(99-digit number)
65745323559762458832…47076660322892349441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.314 × 10⁹⁹(100-digit number)
13149064711952491766…94153320645784698881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.629 × 10⁹⁹(100-digit number)
26298129423904983533…88306641291569397761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
5.259 × 10⁹⁹(100-digit number)
52596258847809967066…76613282583138795521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.051 × 10¹⁰⁰(101-digit number)
10519251769561993413…53226565166277591041
Verify on FactorDB ↗Wolfram Alpha ↗

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 — 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
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 × 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 882017

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 dae798382fc58f5780904283a64953c9674852a1d00dbe6ad2076794059d2b83

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 #882,017 on Chainz ↗
Circulating Supply:57,635,280 XPM·at block #6,798,904 · updates every 60s
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