SATOSHI'S NUMBERS 369 CLOCK
Bitcoin is designed to mine 6 blocks per hour >> one block on average every ~10 minutes.
24 hours in a day 2+4= 6
That works out to 144 blocks per day 1+4+4= 9
52560 blocks per year 5+2+5+6+0=18 1+8= 9
52704 blocks per leap year 5+2+7+0+4=18 1+8= 9
21 Million coins: 2+1+0+0+0+0+0+0= 3
33 Halvings: 3+3= 6
Difficulty adjusts every 2016 blocks: 2+0+1+6= 9
The block reward halving happens every 210,000th block (approximately every four years) 2+1+0+0+0+0= 3
~ Based on a tweet by @level39