Which number is not in scientific notation?
A: 6 ⋅ 1025
B: 2.01 ⋅ 10−2
C: 1.3 ⋅ 10−4
D: 0.5 ⋅ 103
A: 6 ⋅ 1025
B: 2.01 ⋅ 10−2
C: 1.3 ⋅ 10−4
D: 0.5 ⋅ 103