Block #6,784,925

1CCLength 12★★★★☆

Cunningham Chain of the First Kind · Discovered 4/5/2026, 10:47:52 PM · Difficulty 10.9809 · 229 confirmations

1CC

Cunningham Chain of the First Kind

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

Block Header

Block Hash

07d5ed680932eb414e3b9ce6bbf8f7cd54027fd8c388446f5edec6888178bda8

View on Chainz ↗

Height

#6,784,925

Difficulty

10.980867

Transactions

Size

190 B

Version

536870912

Bits

0afb1a14

Nonce

1,528,934,383

Timestamp

4/5/2026, 10:47:52 PM

Confirmations

229

Merkle Root

7b0feac2adce3b6b177f6c59c40590d97955a20ad31a74fee30814d4f0c6b775

Transactions (1)

Coinbase7b0feac2adce3b…0814d4f0c6b775

1 in → 1 out8.1790 XPM101 B

AMrLYUQN…jwjifxiz

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.

1.145 × 10⁹³(94-digit number)

11455461589306856000…02101736422468900039

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.

origin − 1

1.145 × 10⁹³(94-digit number)

11455461589306856000…02101736422468900039

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^1 × origin − 1

2.291 × 10⁹³(94-digit number)

22910923178613712000…04203472844937800079

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^2 × origin − 1

4.582 × 10⁹³(94-digit number)

45821846357227424001…08406945689875600159

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^3 × origin − 1

9.164 × 10⁹³(94-digit number)

91643692714454848003…16813891379751200319

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^4 × origin − 1

1.832 × 10⁹⁴(95-digit number)

18328738542890969600…33627782759502400639

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^5 × origin − 1

3.665 × 10⁹⁴(95-digit number)

36657477085781939201…67255565519004801279

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^6 × origin − 1

7.331 × 10⁹⁴(95-digit number)

73314954171563878402…34511131038009602559

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^7 × origin − 1

1.466 × 10⁹⁵(96-digit number)

14662990834312775680…69022262076019205119

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^8 × origin − 1

2.932 × 10⁹⁵(96-digit number)

29325981668625551361…38044524152038410239

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^9 × origin − 1

5.865 × 10⁹⁵(96-digit number)

58651963337251102722…76089048304076820479

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^10 × origin − 1

1.173 × 10⁹⁶(97-digit number)

11730392667450220544…52178096608153640959

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^11 × origin − 1

2.346 × 10⁹⁶(97-digit number)

23460785334900441088…04356193216307281919

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.

★★★★☆

Rarity

ExceptionalChain length 12

Around 1 in 10,000 blocks. A significant mathematical achievement.

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, …

Cross-reference on Chainz Explorer