Since you don't specify base b, that means the answer will be the same in any base from 2 to 10:
11011_2 * (2 - 1) + 1001 = 100100 = 36_10
11011_3 * (3 - 1) + 1001 = 100100 = 252_10
11011_4 * (4 - 1) + 1001 = 100100 = 1040_10
11011_5 * (5 - 1) + 1001 = 100100 = 3150_10
11011_6 * (6 - 1) + 1001 = 100100 = 7812_10
11011_7 * (7 - 1) + 1001 = 100100 = 16856_10
11011_8 * (8 - 1) + 1001 = 100100 = 32832_10
11011_9 * (9 - 1) + 1001 = 100100 = 59130_10
11011_10*(10-1) + 1001 = 100100 = 100100_10