NEW YORK (AP) _ Newspaper heiress Iphigene Ochs Sulzberger, whose verve and wit influenced The New York Times and whose powerful acquaintances included every president from Coolidge to Kennedy, died in her sleep early Monday. She was 97.

Mrs. Sulzberger died of natural causes at her home in Stamford, Conn., said Nancy Flynn, assistant to Arthur Ochs Sulzberger, Mrs. Sulzberger's son and publisher of the Times.

''You cannot think of Iphigene Ochs Sulzberger without thinking of The New York Times. And it is impossible to imagine the Times without Iphigene Sulzberger,'' former Times editor Harrison E. Salisbury wrote in the introduction to her memoirs, ''Iphigene: My Life and The New York Times.''

Funeral services were set for Wednesday at Temple Emanu-El in Manhattan.

As a trustee of the family fortune and as the daughter, wife, mother-in-law and mother of Times publishers, Mrs. Sulzberger enjoyed power and prominence.

She was the White House guest of every president from Calvin Coolidge during the Roaring Twenties to John F. Kennedy in the '60s, and knew British Prime Minister Winston Churchill, Japanese Emperor Hirohito, the Shah of Iran and other heads of state.

''The more one has seen and experienced in life, the more questions one raises, the more one realizes that, as my coat of arms says, 'Nothing is impossible,''' she said in her memoirs.

In his book about The New York Times, ''The Kingdom and the Power,'' Gay Talese theorized that if her father, Times Publisher Adolph S. Ochs, had permitted it, Mrs. Sulzberger ''might have become a journalist, a crusading sort urging reform.''

But she disagreed, saying a single course at the Columbia School of Journalism represented ''the first and only time I aspired to become a journalist.''

Instead, Ochs appointed her to the Times board of directors when she was in her 20s.

After he died in April 1935, she was one of three trustees - along with her husband and then her son - of the Ochs estate, which owns the controlling interest in the newspaper.

To perpetuate her father's dream, Mrs. Sulzberger's four children and her grandchildren entered into agreements that will continue family control of the Times and related properties indefinitely.

Newspapering was a birthright for Iphigene Bertha Ochs, whose grandfather was Rabbi Isaac M. Wise, a founder of Judaism's Reform movement.

On Sept. 19, 1892 - the night she was born in Cincinnati - her father, then publisher of the Chattanooga Times, was in New York fighting to get smaller newspapers accepted in The Associated Press.

Four years later, Ochs became publisher of The New York Times; by 1899, he owned it. On Jan. 18, 1904, young Iphigene helped lay the cornerstone for the paper's new building at Times Square.

Sometime later, her father, dismayed by Iphigene's fascination with ''vulgar'' comics in competitor papers, started the Times' first and last comic strip, ''The Roosevelt Bears.''

Young Iphigene judged their adventures ''wordy and uninteresting,'' and the bears became extinct after a year and a half.

Salisbury said Iphigene's impish nature emerged in childhood, and she remained irrepressible as an adult.

She recalled meeting many interesting people as a child: Mark Twain; Andrew Carnegie; President William Howard Taft; Adm. Richard Byrd.

At age 9, she signed a thank-you note to President Theodore Roosevelt ''love and kisses''; at 12, she was expelled for ''impertinence'' from Dr. Sachs' School for Girls; at 16, she enjoyed rides at Coney Island with Guglielmo Marconi, inventor of the wireless.

She studied economics at Barnard College, and graduated as an ''A'' student despite having dyslexia, a learning disability unknown at the time.

During college, she did volunteer work, and briefly became a socialist, which ''made quite an impression at home,'' she wrote in her memoirs.

She became engaged to Arthur Hays Sulzberger at a romantic-looking park in Spartanburg, S.C., that ''turned out to be the grounds of the local lunatic asylum,'' she recalled.

They were married on Nov. 17, 1917, capping their Washington honeymoon with a White House meeting with President Woodrow Wilson.

When Ochs died, Sulzberger succeeded him as publisher of the Times.

As an adult, Mrs. Sulzberger continued to rub elbows with the famous. She met Eleanor Roosevelt, dined with Chiang Kai-shek, and had coffee with Israeli Prime Minister Golda Meir.

But she wielded her influence subtly.

In 1937, she arranged for an angry President Franklin D. Roosevelt to invite her husband to lunch so the two men could iron out their differences. She didn't tell Sulzberger how the invitation came about.

She wrote letters to the editor, using her own stationery but signing the names of deceased relatives. The letters were printed if they met the same Times criteria applied to other letters.

''The impression was shared by nearly all senior Timesmen that Iphigene, in her gentle way, her friendly hints and reminders, in her very existence as Ochs' only offspring and the direct heir to his fortune, exerted a tremendous influence on the character of the Times,'' Talese wrote.

In 1941, her alarm at a lack of required American history courses in schools led to a Times story that triggered nationwide support and legislation in some states.

She helped start a vacation camp program for the elderly, and became a benefactor of the Metropolitan Museum of Art and a founding member of the Central Park Conservancy.

After her children were grown, Mrs. Sulzberger worked to expand the Times' coverage of women's affairs and its circulation in schools.

Her husband retired in 1961. Their son-in-law, Orvil E. Dryfoos, was publisher until he died in May 1963. Their son, nicknamed ''Punch,'' has been publisher since then; their grandson, Arthur Ochs Sulzberger Jr., is deputy publisher.

Their other children are Marian Sulzberger Heiskell, the widow of Orvil Dryfoos and wife of Andrew Heiskell, retired chairman of Time Inc.; Ruth Sulzberger Holmberg, publisher of the Chattanooga Times; and Dr. Judith P. Sulzberger, a New York City physician.

They had 13 grandchildren and 24 great-grandchildren.

After her husband died, Mrs. Sulzberger forced herself to resume an active life.

At age 81, she had ''one of the most memorable experiences of my life,'' becoming one of the first Americans to visit China in 25 years.

During dinner with Prime Minister Chou En-lai, she persuaded the leader to allow a Times correspondent into China.