Senator Bernie Sanders announced on Sunday that he had raised $46.5 million in February, a sum that gives him a significant financial advantage over all of his rivals aside from the self-funding billionaire Michael R. Bloomberg as the number of states holding primaries expands widely in March, beginning on Tuesday.

The Sanders campaign, which was already running television ads in most of the states that will vote that day — Super Tuesday — said it had reserved ads in five states that will vote on March 10 (including Michigan and Washington) and four big-market states that cast their ballots on March 17 (Arizona, Florida, Illinois and Ohio).

The $46.5 million haul is by far the largest of any 2020 candidate in any single month but not far from what Mr. Sanders raised four years ago in February in his campaign against Hillary Clinton, when he collected $43.5 million.

Senator Elizabeth Warren’s campaign also announced a substantial February fund-raising total on Sunday, saying it had slightly exceeded its goal of bringing in $29 million. And the campaign of former Vice President Joseph R. Biden Jr. said it raised $18 million last month.