A wife of the Russian billionaire Roman Abramovich has become the new owner of six Upper East Side properties, including a block of townhouses being combined into a mega-mansion.

The transactions, totaling $92.3 million, were apparently part of a property settlement between Mr. Abramovich and his third wife, Darya Zhukova, who announced their split last year. They were also among the largest closings for the month of September, according to New York City property records.

But the single biggest sale last month, at $42 million, was a penthouse covering the entire 77th floor of One57, the vitreous skyscraper in the heart of Manhattan’s Billionaires’ Row, at 157 West 57th Street. Monthly carrying charges are $15,214. The unnamed European seller took a loss, however, having paid nearly $47.8 million for the unit in May 2015. The 6,240-square-foot apartment has four bedrooms and five and a half baths, not to mention breathtaking views.

Brooklyn had a record-breaking closing in September. A grand historic brownstone in Bedford-Stuyvesant sold for nearly $6.3 million, which was not only above the $6 million asking price but also the highest price ever paid for a residence in the neighborhood.