Home/Chain Registry/Block #566,721

Block #566,721

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 5/29/2014, 2:57:47 AM · Difficulty 10.9660 · 6,228,136 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
1df11ab03c004bdaaed06f3c571bf8fb31969d079c5f1f00aca6cda35fe47d4d

Height

#566,721

Difficulty

10.966049

Transactions

1

Size

628 B

Version

2

Bits

0af74efc

Nonce

3,094

Timestamp

5/29/2014, 2:57:47 AM

Confirmations

6,228,136

Merkle Root

b926f7a4312289363d43d0b843246f32b2b96f5762cf620ef3f66d1359a291bf
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.

7.799 × 10⁹¹(92-digit number)
77993248236768188303…09788468624543348580
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
7.799 × 10⁹¹(92-digit number)
77993248236768188303…09788468624543348579
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.559 × 10⁹²(93-digit number)
15598649647353637660…19576937249086697159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.119 × 10⁹²(93-digit number)
31197299294707275321…39153874498173394319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
6.239 × 10⁹²(93-digit number)
62394598589414550642…78307748996346788639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.247 × 10⁹³(94-digit number)
12478919717882910128…56615497992693577279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.495 × 10⁹³(94-digit number)
24957839435765820257…13230995985387154559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.991 × 10⁹³(94-digit number)
49915678871531640514…26461991970774309119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
9.983 × 10⁹³(94-digit number)
99831357743063281028…52923983941548618239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.996 × 10⁹⁴(95-digit number)
19966271548612656205…05847967883097236479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.993 × 10⁹⁴(95-digit number)
39932543097225312411…11695935766194472959
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 566721

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 1df11ab03c004bdaaed06f3c571bf8fb31969d079c5f1f00aca6cda35fe47d4d

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 #566,721 on Chainz ↗
Circulating Supply:57,602,886 XPM·at block #6,794,856 · updates every 60s
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