331
Because it can be divided by other numbers not by itself nor 1 For Example: 993 / 3 = 331: which can be divided
331
0.0185
No, its not a prime. 3 x 331 = 993
2.6667
993
2.5
what iswatson993
1, 2, 3, 6, 331, 662, 993, 1986 -1, -2, -3, -6, -331, -662, -993, -1986
0.0081
Why don't you just search it? But the answer is 0.39130434782