Block #2,640,993

TWN0b.efbf3f

Discovered 5/1/2018, 5:02:19 AM · Difficulty 11.6027 · 4,150,001 confirmations

Block Header

Block Hash

63d1431495585b4f3114da8e9badd5d654d082f130b3965629503ce708f8b3ff

View on Chainz ↗

Height

#2,640,993

Difficulty

11.602714

Transactions

Size

3.45 KB

Version

Bits

0b9a4b78

Nonce

1,818,343,801

Timestamp

5/1/2018, 5:02:19 AM

Confirmations

4,150,001

Merkle Root

2fffab356efbcbbd258c983ec6fdf54fa1ca3d1fdb8e57b399eefb31b80412e3

Transactions (2)

Coinbaseb45178e4e660f6…9a4d5ca2845bdb

1 in → 1 out7.4600 XPM110 B

Adqah8zh…1WwoHJ9t

2606a9f0a9080e…ab32c4910d8ec6

22 in → 2 out200.0100 XPM3.25 KB

AGbUPi3v…cpf6KNJa AJxMdZmR…ehXuV253

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.

2.614 × 10⁹³(94-digit number)

26144030990531777217…13008764592050571760

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 TWN0b.efbf3f formula:

Cross-reference on Chainz Explorer