Block #31,097

TWN07.fdc1c0

Discovered 7/13/2013, 9:59:02 PM · Difficulty 7.9881 · 6,758,435 confirmations

Block Header

Block Hash

0b280565b52e896ad3754722599c137b6db252e5a29e15a9ae7b03a922d599d1

View on Chainz ↗

Height

#31,097

Difficulty

7.988096

Transactions

Size

201 B

Version

Bits

07fcf3d7

Nonce

175

Timestamp

7/13/2013, 9:59:02 PM

Confirmations

6,758,435

Merkle Root

dcd0fba3ac28a74f84794ddd57704cfce4d7eb75de43307cfd9dd32638444a1d

Transactions (1)

Coinbasedcd0fba3ac28a7…9dd32638444a1d

1 in → 1 out15.6500 XPM108 B

AHVYrbCG…NMzaD4fP

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.

5.611 × 10¹⁰¹(102-digit number)

56114131960172835775…42607865589910571570

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 TWN07.fdc1c0 formula:

Cross-reference on Chainz Explorer