2. Multiply each bit by its corresponding power of 2 and add all the terms up.
1010 1001 0001 0000 0000 0000 0000 0000 0000 0000 0000 0110 1101(2) =
(1 × 251 + 0 × 250 + 1 × 249 + 0 × 248 + 1 × 247 + 0 × 246 + 0 × 245 + 1 × 244 + 0 × 243 + 0 × 242 + 0 × 241 + 1 × 240 + 0 × 239 + 0 × 238 + 0 × 237 + 0 × 236 + 0 × 235 + 0 × 234 + 0 × 233 + 0 × 232 + 0 × 231 + 0 × 230 + 0 × 229 + 0 × 228 + 0 × 227 + 0 × 226 + 0 × 225 + 0 × 224 + 0 × 223 + 0 × 222 + 0 × 221 + 0 × 220 + 0 × 219 + 0 × 218 + 0 × 217 + 0 × 216 + 0 × 215 + 0 × 214 + 0 × 213 + 0 × 212 + 0 × 211 + 0 × 210 + 0 × 29 + 0 × 28 + 0 × 27 + 1 × 26 + 1 × 25 + 0 × 24 + 1 × 23 + 1 × 22 + 0 × 21 + 1 × 20)(10) =
(2 251 799 813 685 248 + 0 + 562 949 953 421 312 + 0 + 140 737 488 355 328 + 0 + 0 + 17 592 186 044 416 + 0 + 0 + 0 + 1 099 511 627 776 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 64 + 32 + 0 + 8 + 4 + 0 + 1)(10) =
(2 251 799 813 685 248 + 562 949 953 421 312 + 140 737 488 355 328 + 17 592 186 044 416 + 1 099 511 627 776 + 64 + 32 + 8 + 4 + 1)(10) =
2 974 178 953 134 189(10)
The number 1010 1001 0001 0000 0000 0000 0000 0000 0000 0000 0000 0110 1101(2) converted from an unsigned binary (in base 2) and written as a positive integer (with no sign) in decimal system (in base ten):
1010 1001 0001 0000 0000 0000 0000 0000 0000 0000 0000 0110 1101(2) = 2 974 178 953 134 189(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.