XPM Prime Explorer symbol
XPMPrime Explorer
Home/Chain Registry/Block #2,642,484

Block #2,642,484

2CCLength 11β˜…β˜…β˜…β˜†β˜†

Cunningham Chain of the Second Kind Β· Discovered 5/1/2018, 6:17:12 PM Β· Difficulty 11.6540 Β· 4,188,183 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
7c6c6c072164e3e1b3b5a4190a7b7cb89768915aaf1a9cd7094ad8ef3f9fca1f
View on Chainz β†—

Difficulty

11.653975

Transactions

1

Size

200 B

Version

2

Bits

0ba76ae1

Nonce

638,072,010

Timestamp

5/1/2018, 6:17:12 PM

Confirmations

4,188,183

Merkle Root

c24d6967ccf2306707fab3b8c610049b6ee282d9e6cb87d85d83dbb0ffbe2175
Transactions (1)
Coinbasec24d6967ccf230…83dbb0ffbe2175
1 in β†’ 1 out7.3500 XPM110 B
AXDmLRrZ…qCTYWcus
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) β€” it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

1.549 Γ— 10⁹⁡(96-digit number)
15496603065060266573…25572690795190829920
Discovered Prime Numbers
p_k = 2^k Γ— 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
1.549 Γ— 10⁹⁡(96-digit number)
15496603065060266573…25572690795190829921
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
2
2^1 Γ— origin + 1
3.099 Γ— 10⁹⁡(96-digit number)
30993206130120533146…51145381590381659841
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
3
2^2 Γ— origin + 1
6.198 Γ— 10⁹⁡(96-digit number)
61986412260241066292…02290763180763319681
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
4
2^3 Γ— origin + 1
1.239 Γ— 10⁹⁢(97-digit number)
12397282452048213258…04581526361526639361
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
5
2^4 Γ— origin + 1
2.479 Γ— 10⁹⁢(97-digit number)
24794564904096426517…09163052723053278721
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
6
2^5 Γ— origin + 1
4.958 Γ— 10⁹⁢(97-digit number)
49589129808192853034…18326105446106557441
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
7
2^6 Γ— origin + 1
9.917 Γ— 10⁹⁢(97-digit number)
99178259616385706068…36652210892213114881
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
8
2^7 Γ— origin + 1
1.983 Γ— 10⁹⁷(98-digit number)
19835651923277141213…73304421784426229761
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
9
2^8 Γ— origin + 1
3.967 Γ— 10⁹⁷(98-digit number)
39671303846554282427…46608843568852459521
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
10
2^9 Γ— origin + 1
7.934 Γ— 10⁹⁷(98-digit number)
79342607693108564854…93217687137704919041
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
11
2^10 Γ— origin + 1
1.586 Γ— 10⁹⁸(99-digit number)
15868521538621712970…86435374275409838081
Verify on FactorDB β†—Wolfram Alpha β†—

What this block proved

The miner who found this block proved the existence of 11 consecutive prime numbers forming a Cunningham Chain of the Second Kind. The prime chain origin β€” the large number shown above β€” 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 β†’
β˜…β˜…β˜…β˜†β˜†
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 Γ— 3 Γ— 5 Γ— 7 Γ— …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial β€” that divisibility is part of the proof.

Prime Chain Origin = First Prime Γ— Primorial (2Β·3Β·5Β·7Β·11·…)
Source: Primecoin prime.cpp β€” CheckPrimeProofOfWork()

This is why the origin has many small prime factors β€” those factors are the primorial divisor. The chain then extends from the first prime using the 2CC formula:

2CC: p₁ (first prime), pβ‚‚ = 2p₁ βˆ’ 1, p₃ = 2pβ‚‚ βˆ’ 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 2642484

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 7c6c6c072164e3e1b3b5a4190a7b7cb89768915aaf1a9cd7094ad8ef3f9fca1f

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 β†’ Debug Window β†’ 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 #2,642,484 on Chainz β†—
Circulating Supply:57,889,464 XPMΒ·at block #6,830,666 Β· updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.
Privacy PolicyΒ·
AQZeJoQ81VgeHQBpEYTgvNqV1gnz3L5SvK

Cookie Preferences

We use cookies to enhance your experience. Some are essential for the site to function, while others help us understand how you use the site.

Β·Privacy Policy