More than 171 million Americans will celebrate Halloween this year, with spending on holiday decorations and costumes expected to reach $8.4 billion, according to a survey by the National Retail Federation.

“Retailers are preparing (for Halloween) by offering a wide variety of options in costumes, decorations and candy,” said NRF President Matthew Shay.

So, just where is a lot of that money expected to go? The survey projects that more than $3 billion will be spent on costumes. Here is a look at some of the expected popular choices this year:

Great power, great popularity

Led by Spiderman, flocks of pint-sized superheroes should be seen roaming through neighborhoods this Halloween. Among the NRF survey’s other findings, more children than ever this year will dress up as their favorite superhero, knocking the perpetually popular princess costume from the top spot after an 11-year run.

“This is definitely influenced by the increase of superhero and action movies that were released this year,” NRF spokeswoman Ana Smith told NBC.

“Batman vs. Superman: Dawn of Justice,” “Captain America: Civil War” and “X-Men: Apocalypse” are among the superhero flicks that are generating costume ideas, Smith said.

Politics

It wouldn’t be Halloween in an election year if the presidential candidates weren’t among the top choices. The Donald was also a big seller last year, and due in part to its simplicity — all you really need is a suit and a combover wig to look the part — it should prove quite popular again, even if the real-life candidate himself doesn’t do so well at the ballot box in November.

There are also no shortage of Hillary Clinton ideas, from masks to pantsuits. And they can be easily accessorized with a stack of printed emails or a “basket of deplorables.”

A late entry to the pool of political ideas this year is Ken Bone, the undecided Illinois voter from the second presidential debate who became an internet sensation thanks to his red cardigan sweater, black-rimmed glasses and disposable camera.

Pokemon GO time

The smartphone craze that took the country by storm this summer is providing plenty of ideas for Halloween garb. Couples can dress up as Ash and Misty from the animated series, or there are a variety of trainer outfits available on Amazon.

The Walking Dead

Zombies and other undead beings — many of them no doubt inspired by AMC’s long-running hit drama — remain a trendy pick. According to the NRF survey, nearly 1.4 million adults are expected to lather on makeup and put on tattered clothing to transform themselves into those plodding grave dwellers. Their cultural cache — combined with the ease of putting many zombie outfits together — make this an enduring choice.

May the Force be with you

The release of “Star Wars: The Force Awakens” has spurred renewed interest in the space opera franchise and thus brought back dozens of costume ideas — from bathrobe Jedis to cardboard storm troopers.