Block #2,644,847

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.

3.361 × 10⁹⁷(98-digit number)

33616595555544481082…24824332495028223999

Discovered Prime Numbers

Lower: 2^k × origin − 1 | Upper: 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.

Level 0 — Twin Prime Pair (origin ± 1)

origin − 1

3.361 × 10⁹⁷(98-digit number)

33616595555544481082…24824332495028223999

Verify on FactorDB ↗Wolfram Alpha ↗

origin + 1

3.361 × 10⁹⁷(98-digit number)

33616595555544481082…24824332495028224001

Verify on FactorDB ↗Wolfram Alpha ↗

Difference: origin + 1 − origin − 1 = 2 (twin primes ✓)

Level 1 — Twin Prime Pair (2^1 × origin ± 1)

2^1 × origin − 1

6.723 × 10⁹⁷(98-digit number)

67233191111088962164…49648664990056447999

Verify on FactorDB ↗Wolfram Alpha ↗

2^1 × origin + 1

6.723 × 10⁹⁷(98-digit number)

67233191111088962164…49648664990056448001

Verify on FactorDB ↗Wolfram Alpha ↗

Difference: 2^1 × origin + 1 − 2^1 × origin − 1 = 2 (twin primes ✓)

Level 2 — Twin Prime Pair (2^2 × origin ± 1)

2^2 × origin − 1

1.344 × 10⁹⁸(99-digit number)

13446638222217792432…99297329980112895999

Verify on FactorDB ↗Wolfram Alpha ↗

2^2 × origin + 1

1.344 × 10⁹⁸(99-digit number)

13446638222217792432…99297329980112896001

Verify on FactorDB ↗Wolfram Alpha ↗

Difference: 2^2 × origin + 1 − 2^2 × origin − 1 = 2 (twin primes ✓)

Level 3 — Twin Prime Pair (2^3 × origin ± 1)

2^3 × origin − 1

2.689 × 10⁹⁸(99-digit number)

26893276444435584865…98594659960225791999

Verify on FactorDB ↗Wolfram Alpha ↗

2^3 × origin + 1

2.689 × 10⁹⁸(99-digit number)

26893276444435584865…98594659960225792001

Verify on FactorDB ↗Wolfram Alpha ↗

Difference: 2^3 × origin + 1 − 2^3 × origin − 1 = 2 (twin primes ✓)

Level 4 — Twin Prime Pair (2^4 × origin ± 1)

2^4 × origin − 1

5.378 × 10⁹⁸(99-digit number)

53786552888871169731…97189319920451583999

Verify on FactorDB ↗Wolfram Alpha ↗

2^4 × origin + 1

5.378 × 10⁹⁸(99-digit number)

53786552888871169731…97189319920451584001

Verify on FactorDB ↗Wolfram Alpha ↗

Difference: 2^4 × origin + 1 − 2^4 × origin − 1 = 2 (twin primes ✓)

Level 5 — Twin Prime Pair (2^5 × origin ± 1)

2^5 × origin − 1

1.075 × 10⁹⁹(100-digit number)

10757310577774233946…94378639840903167999

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 Bi-Twin Chain. 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 TWN formula:

TWN: twin pairs (p, p+2) where p = origin/primorial − 1 and p+2 = origin/primorial + 1

Cross-reference on Chainz Explorer

Block #2,644,847

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