A week ago, Adrian Lopez, 17, was just an average high school student in Eastvale, Calif. But after a digital flyer he made inviting friends to Huntington Beach for his birthday went viral — to the point of attracting thousands of strangers to the beach and to an event space in Los Angeles — he’s become a household name on social media.

He made the invitation on Monday, specifying a time (7:30 p.m.), place (fire pits) and date (May 22). “Slide tru this Saturday we finna turn up!!!!” read the bottom of the image, which was titled “Adrian’s Kickback.”

“It was meant to be for my school,” Mr. Lopez said.

In an attempt to drum up more interest, Mr. Lopez’s friend, Yahir Hernandez, 16, posted the flier to Snapchat, then to his personal TikTok account. “Tuesday morning was when Yahir made the TikTok,” Mr. Lopez said. “I was on my way to school and it only had like 40 likes, so I ignored it.” But over the next few days the video took off. Something about the specifics of the invite felt hilarious to those who encountered it. “Who is Adrian?” people commented.

The video took hold on TikTok’s powerful “For You” recommendation algorithm and gained mass distribution. Overnight, it became a meme. Internet celebrities and creators including the music artist 24kGoldn, members of FaZe Clan and Noah Beck posted about it. By the weekend of the event, TikTok videos with the hashtag #adrianskickback had attracted nearly 280 million views.