Block #1,661,380

TWN0a.e34f57

Discovered 7/6/2016, 4:56:27 AM · Difficulty 10.7324 · 5,131,394 confirmations

Block Header

Block Hash

1a4b74df7e859223bc055f5a9f4fe97f8a153640f44754076583232ad93c3ea6

View on Chainz ↗

Height

#1,661,380

Difficulty

10.732420

Transactions

Size

28.36 KB

Version

Bits

0abb7fdb

Nonce

48,342,172

Timestamp

7/6/2016, 4:56:27 AM

Confirmations

5,131,394

Merkle Root

76fb41fc2387466e342b17af9ce51611e69b88911f531bf94546cf7b69ac6f24

Transactions (2)

Coinbase480df5f53161d8…148fb5bf242606

1 in → 1 out8.9600 XPM109 B

APafdzgF…L6kYnB7a

424e4831780de2…0d31c4d1e42a8c

230 in → 2 out1711.4854 XPM28.16 KB

AckR6Juo…yger1Nco ALjKo1Hf…CPfGSo2V

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.

5.276 × 10⁹³(94-digit number)

52764885547277575580…32974795871162470460

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 TWN0a.e34f57 formula:

Cross-reference on Chainz Explorer