WASHINGTON — The impact of a partial government shutdown began to ripple across the economy as it stretched into Day 17, with mortgage applications delayed, public companies unable to get approval to raise capital and thousands of Secret Service agents expected to show up for work without pay.

President Trump and congressional Democrats have made little progress in negotiations to end a shutdown that has affected about 800,000 federal workers, many of whom will miss their first paycheck this week, and who owe a combined $249 million in monthly mortgage payments, according to the online real estate firm Zillow.

The shutdown shows no sign of ending soon, with Mr. Trump announcing Monday that he would address the nation on Tuesday evening from the Oval Office to discuss what he called the crisis at the southern border, and the White House saying that he would travel to the border this week as part of his effort to persuade Americans of the need for a wall — the sticking point in negotiations with Democrats.

The standoff is beginning to inflict pain on Americans, whose lives are affected, in one way or another, by the federal government. It is already the second-longest shutdown in history, behind the one that started in December 1995 and lasted 21 days.