TikTok commands the attention of 150 million American users. That's its best defense yet against Biden's threat of a ban.

• TikTok officially has 150 million monthly active users in the US, the company says.

• The app's popularity with younger voters makes a ban politically sensitive, experts say.

• TikTok's user numbers could ultimately be its best defense. It's now a routine for 45% of the US.

TikTok officially has 150 million monthly active users in the US, the company confirmed this week. That means any effort to ban it could face stiff resistance after the app has become part of the routine of 45% of the country.

The user figures come as TikTok CEO Shou Chew is set to testify in front of Congress on Thursday. They also come as the Biden Administration has demanded TikTok's Chinese owners divest their US business or risk getting banned entirely from the US.

TikTok's user numbers show just how much the social media app has taken hold. It's still not to the threshold of Facebook, which logs 266 million monthly active users in the US, but it's not far behind. (Facebook parent Meta doesn't break out Instagram's monthly active users in the US.)

As TikTok's CEO Chew put it: "That's almost half the US coming to TikTok to connect, to create, to share, to learn, or just to have some fun." That number also includes about 5 million businesses that use TikTok as a way to reach customers, he said in a TikTok video on Tuesday.