Home/Chain Registry/Block #901,506

Block #901,506

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/19/2015, 2:54:35 PM · Difficulty 10.9416 · 5,904,317 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
4e177e6e40c7c7f1b9ae3b044fbf951c558b39aa56d2a9fc6cff217b00a8019b

Height

#901,506

Difficulty

10.941607

Transactions

9

Size

8.93 KB

Version

2

Bits

0af10d2d

Nonce

8,996,839

Timestamp

1/19/2015, 2:54:35 PM

Confirmations

5,904,317

Merkle Root

59eda5fa089c4246eb9ff72f02386ec3e152cbd7a0099432d8c20de08e3b4e1c
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.

2.406 × 10⁹⁵(96-digit number)
24062588338449405535…42224023788269490240
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
2.406 × 10⁹⁵(96-digit number)
24062588338449405535…42224023788269490239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.812 × 10⁹⁵(96-digit number)
48125176676898811071…84448047576538980479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
9.625 × 10⁹⁵(96-digit number)
96250353353797622142…68896095153077960959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.925 × 10⁹⁶(97-digit number)
19250070670759524428…37792190306155921919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.850 × 10⁹⁶(97-digit number)
38500141341519048856…75584380612311843839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
7.700 × 10⁹⁶(97-digit number)
77000282683038097713…51168761224623687679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.540 × 10⁹⁷(98-digit number)
15400056536607619542…02337522449247375359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.080 × 10⁹⁷(98-digit number)
30800113073215239085…04675044898494750719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
6.160 × 10⁹⁷(98-digit number)
61600226146430478171…09350089796989501439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.232 × 10⁹⁸(99-digit number)
12320045229286095634…18700179593979002879
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 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.

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 1CC formula:

1CC: 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 901506

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 4e177e6e40c7c7f1b9ae3b044fbf951c558b39aa56d2a9fc6cff217b00a8019b

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 #901,506 on Chainz ↗
Circulating Supply:57,690,670 XPM·at block #6,805,822 · updates every 60s
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