Block #6,784,936

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 4/5/2026, 11:00:22 PM · Difficulty 10.9809 · 218 confirmations

1CC

Cunningham Chain of the First Kind

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

Block Header

Block Hash

e9a6a5ba29869b8ead410327cb3e88cbb0f7d1f1ab0dcf1486d21093e6915861

View on Chainz ↗

Height

#6,784,936

Difficulty

10.980859

Transactions

Size

192 B

Version

536870912

Bits

0afb199b

Nonce

1,554,943,243

Timestamp

4/5/2026, 11:00:22 PM

Confirmations

218

Merkle Root

c21000498a220837ab9124695b33d5344a4a1d4b812d6eba7039725f5b088bc3

Transactions (1)

Coinbasec21000498a2208…39725f5b088bc3

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.

9.967 × 10⁹⁵(96-digit number)

99679520389243203196…15028745100209007359

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

9.967 × 10⁹⁵(96-digit number)

99679520389243203196…15028745100209007359

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^1 × origin − 1

1.993 × 10⁹⁶(97-digit number)

19935904077848640639…30057490200418014719

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^2 × origin − 1

3.987 × 10⁹⁶(97-digit number)

39871808155697281278…60114980400836029439

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^3 × origin − 1

7.974 × 10⁹⁶(97-digit number)

79743616311394562557…20229960801672058879

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^4 × origin − 1

1.594 × 10⁹⁷(98-digit number)

15948723262278912511…40459921603344117759

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^5 × origin − 1

3.189 × 10⁹⁷(98-digit number)

31897446524557825022…80919843206688235519

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^6 × origin − 1

6.379 × 10⁹⁷(98-digit number)

63794893049115650045…61839686413376471039

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^7 × origin − 1

1.275 × 10⁹⁸(99-digit number)

12758978609823130009…23679372826752942079

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^8 × origin − 1

2.551 × 10⁹⁸(99-digit number)

25517957219646260018…47358745653505884159

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^9 × origin − 1

5.103 × 10⁹⁸(99-digit number)

51035914439292520036…94717491307011768319

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^10 × origin − 1

1.020 × 10⁹⁹(100-digit number)

10207182887858504007…89434982614023536639

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.

★★★☆☆

Rarity

RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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