This number is called "twelve factorial" and written 12!, so, for example 4!=4x3x2x1=24. These 479001600 "strings" of the 12 numbers, for example 1,2,3,4,5,6,7,8,9,10,11,12 and 2,4,6,8,10,12,11,9,7,5,3,1, mathematicians call permutations of the 12 numbers rather than combinations.
