The sheer numbers make millennials — those born between 1981 and 1997 — all but impossible to ignore, explains a report from The Real Deal.

Currently 75.4 million strong, millennials surpassed the Baby Boomer generation last year, according to the Pew Research Center. One in five New Yorkers is a millennial, according to data from the U.S. Census Bureau. And their ranks are growing, thanks to an influx of millennial immigrants to the United States.

Their collective spending power is equally enormous. ...