Home/Chain Registry/Block #2,653,117

Block #2,653,117

1CCLength 12★★★★☆

Cunningham Chain of the First Kind · Discovered 5/8/2018, 3:25:31 AM · Difficulty 11.7406 · 4,189,987 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
06a4c4ee6fdd0a427a75df26790c16a65b2b0d717cc90a17b72c9b3b4da0fb0f

Difficulty

11.740577

Transactions

13

Size

4.88 KB

Version

2

Bits

0bbd9678

Nonce

27,299,715

Timestamp

5/8/2018, 3:25:31 AM

Confirmations

4,189,987

Merkle Root

6cf6d9c43eacfbeb4e5ae3003c80c41ce093046f5579e4888dbebcfd9b03e1e0
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.

1.678 × 10⁹⁴(95-digit number)
16788431784359349979…58278121557812203520
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
1.678 × 10⁹⁴(95-digit number)
16788431784359349979…58278121557812203519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.357 × 10⁹⁴(95-digit number)
33576863568718699958…16556243115624407039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
6.715 × 10⁹⁴(95-digit number)
67153727137437399917…33112486231248814079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.343 × 10⁹⁵(96-digit number)
13430745427487479983…66224972462497628159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.686 × 10⁹⁵(96-digit number)
26861490854974959967…32449944924995256319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
5.372 × 10⁹⁵(96-digit number)
53722981709949919934…64899889849990512639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.074 × 10⁹⁶(97-digit number)
10744596341989983986…29799779699981025279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.148 × 10⁹⁶(97-digit number)
21489192683979967973…59599559399962050559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
4.297 × 10⁹⁶(97-digit number)
42978385367959935947…19199118799924101119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
8.595 × 10⁹⁶(97-digit number)
85956770735919871894…38398237599848202239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
1.719 × 10⁹⁷(98-digit number)
17191354147183974378…76796475199696404479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
12
2^11 × origin − 1
3.438 × 10⁹⁷(98-digit number)
34382708294367948757…53592950399392808959
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 12 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
ExceptionalChain length 12
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 2653117

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 06a4c4ee6fdd0a427a75df26790c16a65b2b0d717cc90a17b72c9b3b4da0fb0f

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 #2,653,117 on Chainz ↗
Circulating Supply:57,989,196 XPM·at block #6,843,103 · updates every 60s
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