Home/Chain Registry/Block #846,695

Block #846,695

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/9/2014, 7:23:18 PM · Difficulty 10.9722 · 5,991,528 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
c6123057fd4d20633662504910dc4d20f2e4937247864fa09db3e681a90908a2

Height

#846,695

Difficulty

10.972163

Transactions

8

Size

1.64 KB

Version

2

Bits

0af8dfa5

Nonce

365,060,519

Timestamp

12/9/2014, 7:23:18 PM

Confirmations

5,991,528

Merkle Root

68ed1bb3ee3049767af1593e52476cc5b80c6128002ccacfa7cd92c94d3fc730
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.

6.359 × 10⁹⁶(97-digit number)
63591626675168793372…14577537344839884800
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
6.359 × 10⁹⁶(97-digit number)
63591626675168793372…14577537344839884799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.271 × 10⁹⁷(98-digit number)
12718325335033758674…29155074689679769599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.543 × 10⁹⁷(98-digit number)
25436650670067517349…58310149379359539199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.087 × 10⁹⁷(98-digit number)
50873301340135034698…16620298758719078399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.017 × 10⁹⁸(99-digit number)
10174660268027006939…33240597517438156799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.034 × 10⁹⁸(99-digit number)
20349320536054013879…66481195034876313599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.069 × 10⁹⁸(99-digit number)
40698641072108027758…32962390069752627199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.139 × 10⁹⁸(99-digit number)
81397282144216055517…65924780139505254399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.627 × 10⁹⁹(100-digit number)
16279456428843211103…31849560279010508799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.255 × 10⁹⁹(100-digit number)
32558912857686422206…63699120558021017599
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 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 →
★★☆☆☆
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 1CC formula:

1CC: 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 846695

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 c6123057fd4d20633662504910dc4d20f2e4937247864fa09db3e681a90908a2

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 #846,695 on Chainz ↗
Circulating Supply:57,950,059 XPM·at block #6,838,222 · updates every 60s
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