18, if leading 0s are disallowed.
468, 486, 648, 684, 846, 864.
60: First digit can be any of 5, second any of 4 and last any of the remaining 3, so 5 x 4 x 3
There are 4*4*3*2*1 = 96 such numbers.
Factorial 4 ie 4 x 3 x 2 x 1 = 24
Most people prefer to write numbers using digits since this is far shorter than writing out the relevant words.
24
60
4 x 3 x 2 ie 24
96425 Larger numbers can be made by cascading the powers, but not on here because the notation won't take it.
1023459
Using only arrangements of the given digits: without repeating digits, 15. with repetition, 39. The answer does not include numbers such as 2^3 = 8 or 3^(2+1) = 27
648
468, 486, 648, 684, 846, 864.
9876543210, without using any mathemeatical operations.
976542
It is 0.123459
9876543210