Select 2 unique numbers from 1 to 999999999999999999999
Total possible combinations (ways)
If order does not matter (e.g. most lottery numbers): 500,000,000,000,000,022,442,856,339,037,958,392,774,656 (~5.0E+23 million trillion)
If order matters (e.g. pick3 numbers, permutations, lock combinations, pin-codes): 1,000,000,000,000,000,044,885,712,678,075,916,785,549,312 (~1.0E+24 million trillion)
If order does not matter (e.g. most lottery numbers): 500,000,000,000,000,022,442,856,339,037,958,392,774,656 (~5.0E+23 million trillion)
If order matters (e.g. pick3 numbers, permutations, lock combinations, pin-codes): 1,000,000,000,000,000,044,885,712,678,075,916,785,549,312 (~1.0E+24 million trillion)