Home/Chain Registry/Block #839,938

Block #839,938

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 12/4/2014, 7:11:45 PM · Difficulty 10.9744 · 5,973,025 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
62007d559d8007d72516006134327f46b540416dc6c86cce1b339b9eb0aeb9f7

Height

#839,938

Difficulty

10.974365

Transactions

12

Size

5.09 KB

Version

2

Bits

0af96ff9

Nonce

1,275,408,450

Timestamp

12/4/2014, 7:11:45 PM

Confirmations

5,973,025

Merkle Root

526b7c329fd55bfa058d82fed0b627b03bc9cc5deb7f9be1b60a9b38b9e69b27
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.

4.884 × 10⁹⁵(96-digit number)
48845456345427547358…56094519287278844160
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
4.884 × 10⁹⁵(96-digit number)
48845456345427547358…56094519287278844159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
9.769 × 10⁹⁵(96-digit number)
97690912690855094717…12189038574557688319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.953 × 10⁹⁶(97-digit number)
19538182538171018943…24378077149115376639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.907 × 10⁹⁶(97-digit number)
39076365076342037887…48756154298230753279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
7.815 × 10⁹⁶(97-digit number)
78152730152684075774…97512308596461506559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.563 × 10⁹⁷(98-digit number)
15630546030536815154…95024617192923013119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.126 × 10⁹⁷(98-digit number)
31261092061073630309…90049234385846026239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
6.252 × 10⁹⁷(98-digit number)
62522184122147260619…80098468771692052479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.250 × 10⁹⁸(99-digit number)
12504436824429452123…60196937543384104959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.500 × 10⁹⁸(99-digit number)
25008873648858904247…20393875086768209919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
5.001 × 10⁹⁸(99-digit number)
50017747297717808495…40787750173536419839
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 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
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 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 839938

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 62007d559d8007d72516006134327f46b540416dc6c86cce1b339b9eb0aeb9f7

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 #839,938 on Chainz ↗
Circulating Supply:57,747,746 XPM·at block #6,812,962 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.

Cookie Preferences

We use cookies to enhance your experience. Some are essential for the site to function, while others help us understand how you use the site.

·Privacy Policy