Block #79,776

2CC09.56c05a

Discovered 7/23/2013, 5:33:46 PM · Difficulty 9.2437 · 6,711,583 confirmations

Block Header

Block Hash

e66b445030a2e82c44145e7fb7948c738f3d3f351b93d9365356e43de47d3a23

View on Chainz ↗

Height

#79,776

Difficulty

9.243691

Transactions

Size

392 B

Version

Bits

093e6284

Nonce

5,333

Timestamp

7/23/2013, 5:33:46 PM

Confirmations

6,711,583

Merkle Root

96369186e7c64cb3459ea339d59027bfd58156959317714e1afe928561acc7a8

Transactions (2)

Coinbasebdccaa42a01d29…4f01dceb70492b

1 in → 1 out11.7000 XPM109 B

ASQg39jN…FNNdpkkB

c574b4d47a0b4a…620179f5688898

1 in → 1 out12.0400 XPM192 B

AJ5JDkMB…S91bdMiR

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.

6.902 × 10⁹⁷(98-digit number)

69025047060569037607…83211163106898270410

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 2CC09.56c05a formula:

Cross-reference on Chainz Explorer