Select 21 unique numbers from 1 to 20
Total possible combinations (ways)
If order does not matter (e.g. most lottery numbers): 2,097,152,000,000,000,000,000,000,000 (~2097152000 million trillion)
If order matters (e.g. pick3 numbers, permutations, lock combinations, pin-codes): 2,097,152,000,000,000,000,000,000,000 (~2097152000 million trillion)
If order does not matter (e.g. most lottery numbers): 2,097,152,000,000,000,000,000,000,000 (~2097152000 million trillion)
If order matters (e.g. pick3 numbers, permutations, lock combinations, pin-codes): 2,097,152,000,000,000,000,000,000,000 (~2097152000 million trillion)