Mr. Bloomberg’s campaign manager, Kevin Sheekey, called the extraordinary use of Mr. Bloomberg’s personal wealth a “down payment’ in a statement.

“Our first month’s filing represents a down payment and commitment in all 50 states to defeat Donald Trump, and it shows we have the resources and plan necessary to take him on,” Mr. Sheekey said.

But in a party defined in no small part by concerns about inequality and economic power concentrated in the hands of the wealthy, Mr. Bloomberg’s fortune — estimated at well above $50 billion — is also a source of discomfort to many Democrats, and his lavishly funded candidacy has drawn sharp criticism from populist liberals, like Mr. Sanders and Ms. Warren.

Mr. Bloomberg’s finances are largely opaque, and they are almost certainly the most complex of all the Democratic presidential candidates. He has not released any tax returns since entering the Democratic primary, and his campaign has postponed filing a personal financial disclosure form until late March, after many of the states he is contesting will already have voted.

The way that Mr. Bloomberg has structured some of his payments offers limited visibility into his spending, including $15 million paid to his company, Bloomberg L.P., that mostly covered the period before he declared his candidacy, and another $12 million to Hawkfish, a technology firm he formed last year.

Still, the report offered a partial window into just how many consulting firms and strategists Mr. Bloomberg is employing and how much some his longtime advisers are paid.

One of the biggest payments went to Doug Schoen, a longtime pollster for Mr. Bloomberg and a Democratic strategist who has appeared often on Fox News. He was paid $3.2 million for polling and is owed nearly $4 million more — for a total of almost $7.2 million in less than two months.