When measured in U.S. dollar bills, a million dollars weigh 2,202.6 pounds. The denomination of bills has a big effect on the weight.
A million dollars in $1 bills is also equal to 1 metric ton but weighs about 1.1 tons by U.S. measure. Each time the denomination of the bills is increased, the weight of a million dollars decreases significantly. When weighed in $100 bills, a million weighs approximately 22 pounds.
Of course, the same is true of how much space a million dollars takes up. U.S. currency is 0.0043 inch thick. A stack of a million dollars in $1 bills would measure 358.33 feet tall, but if you use $20 bills, the stack is only 3.58 feet tall.
Paper currency weighs 1 gram regardless of the denomination. One could easily fit $1 million in cash into a rolling suitcase for travel, though electronic bank transfers are generally used instead of cash for transactions involving large sums of money.