Home/Chain Registry/Block #399,674

Block #399,674

TWNLength 11★★★☆☆

Bi-Twin Chain · Discovered 2/11/2014, 1:42:08 PM · Difficulty 10.4284 · 6,445,648 confirmations

TWN
Bi-Twin Chain

Interleaved pairs of primes that differ by 2, forming twin prime pairs at each level.

Block Header
Block Hash
e7b92d4e6b8b6f02ff3a6c0a1f49d11ab87c13135fe88e5faf611a242bb7809d

Height

#399,674

Difficulty

10.428416

Transactions

7

Size

3.22 KB

Version

2

Bits

0a6daca8

Nonce

65,939

Timestamp

2/11/2014, 1:42:08 PM

Confirmations

6,445,648

Merkle Root

a42419a77055270cbf4b653e818e2ff939454c17973a445e18a8f954058e43fc
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.

6.484 × 10⁹⁶(97-digit number)
64844582141695481608…47453789497122599500
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
6.484 × 10⁹⁶(97-digit number)
64844582141695481608…47453789497122599499
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
6.484 × 10⁹⁶(97-digit number)
64844582141695481608…47453789497122599501
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
1.296 × 10⁹⁷(98-digit number)
12968916428339096321…94907578994245198999
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.296 × 10⁹⁷(98-digit number)
12968916428339096321…94907578994245199001
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
2.593 × 10⁹⁷(98-digit number)
25937832856678192643…89815157988490397999
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.593 × 10⁹⁷(98-digit number)
25937832856678192643…89815157988490398001
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
5.187 × 10⁹⁷(98-digit number)
51875665713356385286…79630315976980795999
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
5.187 × 10⁹⁷(98-digit number)
51875665713356385286…79630315976980796001
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
1.037 × 10⁹⁸(99-digit number)
10375133142671277057…59260631953961591999
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.037 × 10⁹⁸(99-digit number)
10375133142671277057…59260631953961592001
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
2.075 × 10⁹⁸(99-digit number)
20750266285342554114…18521263907923183999
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.

View full Prime Chain Discovery page →
★★★☆☆
Rarity
RareChain length 11
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
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 399674

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 e7b92d4e6b8b6f02ff3a6c0a1f49d11ab87c13135fe88e5faf611a242bb7809d

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 #399,674 on Chainz ↗
Circulating Supply:58,007,015 XPM·at block #6,845,321 · updates every 60s
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