Home/Chain Registry/Block #6,784,932

Block #6,784,932

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/5/2026, 10:57:25 PM · Difficulty 10.9809 · 246 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
0e9a564e704dc24cb68017f9c0d6f104bc019bbfce57eb12d4a8105ef6ddb5a1

Difficulty

10.980854

Transactions

1

Size

192 B

Version

536870912

Bits

0afb1943

Nonce

177,722,007

Timestamp

4/5/2026, 10:57:25 PM

Confirmations

246

Merkle Root

298166f577f78dc2ae0442225d6b9a904d9a681fa36f3e6a4c67e46458eedaa0
Transactions (1)
1 in → 1 out8.1790 XPM101 B
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.

4.959 × 10⁹⁷(98-digit number)
49596520482702747990…29877955994347796480
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
4.959 × 10⁹⁷(98-digit number)
49596520482702747990…29877955994347796481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.919 × 10⁹⁷(98-digit number)
99193040965405495980…59755911988695592961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.983 × 10⁹⁸(99-digit number)
19838608193081099196…19511823977391185921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.967 × 10⁹⁸(99-digit number)
39677216386162198392…39023647954782371841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.935 × 10⁹⁸(99-digit number)
79354432772324396784…78047295909564743681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.587 × 10⁹⁹(100-digit number)
15870886554464879356…56094591819129487361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.174 × 10⁹⁹(100-digit number)
31741773108929758713…12189183638258974721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.348 × 10⁹⁹(100-digit number)
63483546217859517427…24378367276517949441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.269 × 10¹⁰⁰(101-digit number)
12696709243571903485…48756734553035898881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.539 × 10¹⁰⁰(101-digit number)
25393418487143806970…97513469106071797761
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 6784932

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 0e9a564e704dc24cb68017f9c0d6f104bc019bbfce57eb12d4a8105ef6ddb5a1

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 #6,784,932 on Chainz ↗
Circulating Supply:57,525,358 XPM·at block #6,785,177 · updates every 60s