Home/Chain Registry/Block #857,141

Block #857,141

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/17/2014, 2:59:51 PM · Difficulty 10.9677 · 5,986,098 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
3231cf0ba6e6c971d3f40350ec543aa7f357cba1800d0f59d99ce05daf969cd4

Height

#857,141

Difficulty

10.967658

Transactions

6

Size

1.24 KB

Version

2

Bits

0af7b870

Nonce

32,626,676

Timestamp

12/17/2014, 2:59:51 PM

Confirmations

5,986,098

Merkle Root

b8f331ee289b7c8c863f929282b70ad696e5ab27590065d640cb6f95f0d53efc
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.

6.623 × 10⁹⁵(96-digit number)
66236737283969752195…18304061592298826880
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
6.623 × 10⁹⁵(96-digit number)
66236737283969752195…18304061592298826881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.324 × 10⁹⁶(97-digit number)
13247347456793950439…36608123184597653761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.649 × 10⁹⁶(97-digit number)
26494694913587900878…73216246369195307521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.298 × 10⁹⁶(97-digit number)
52989389827175801756…46432492738390615041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.059 × 10⁹⁷(98-digit number)
10597877965435160351…92864985476781230081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.119 × 10⁹⁷(98-digit number)
21195755930870320702…85729970953562460161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.239 × 10⁹⁷(98-digit number)
42391511861740641404…71459941907124920321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
8.478 × 10⁹⁷(98-digit number)
84783023723481282809…42919883814249840641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.695 × 10⁹⁸(99-digit number)
16956604744696256561…85839767628499681281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.391 × 10⁹⁸(99-digit number)
33913209489392513123…71679535256999362561
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 10 consecutive prime numbers forming a Cunningham Chain of the Second 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
UncommonChain length 10
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 2CC formula:

2CC: 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 857141

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 3231cf0ba6e6c971d3f40350ec543aa7f357cba1800d0f59d99ce05daf969cd4

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 #857,141 on Chainz ↗
Circulating Supply:57,990,286 XPM·at block #6,843,238 · updates every 60s
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