Home/Chain Registry/Block #89,671

Block #89,671

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 7/30/2013, 1:22:55 PM · Difficulty 9.2548 · 6,701,505 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
de7be965faa434021e380db9d7e4958bf652888a42f2a8807b5e1ece4a7a52a3

Height

#89,671

Difficulty

9.254768

Transactions

11

Size

3.75 KB

Version

2

Bits

09413879

Nonce

152,610

Timestamp

7/30/2013, 1:22:55 PM

Confirmations

6,701,505

Merkle Root

3a3614a16ae50192f9f25842c8ac5ea89ce52de7efa9a619e5a93795dec3825e
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.

6.888 × 10¹⁰⁶(107-digit number)
68882170099975450499…54955248604097580640
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
6.888 × 10¹⁰⁶(107-digit number)
68882170099975450499…54955248604097580639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.377 × 10¹⁰⁷(108-digit number)
13776434019995090099…09910497208195161279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.755 × 10¹⁰⁷(108-digit number)
27552868039990180199…19820994416390322559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.510 × 10¹⁰⁷(108-digit number)
55105736079980360399…39641988832780645119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.102 × 10¹⁰⁸(109-digit number)
11021147215996072079…79283977665561290239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.204 × 10¹⁰⁸(109-digit number)
22042294431992144159…58567955331122580479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.408 × 10¹⁰⁸(109-digit number)
44084588863984288319…17135910662245160959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.816 × 10¹⁰⁸(109-digit number)
88169177727968576638…34271821324490321919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.763 × 10¹⁰⁹(110-digit number)
17633835545593715327…68543642648980643839
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9
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 89671

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 de7be965faa434021e380db9d7e4958bf652888a42f2a8807b5e1ece4a7a52a3

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 #89,671 on Chainz ↗
Circulating Supply:57,573,337 XPM·at block #6,791,175 · updates every 60s
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