Selena Gomez celebrates 31st birthday with friends and 'Barbie': 'I am thankful for so much in my life'

Selena Gomez's birthday celebration was quite the blowout.

The singer and actress turned 31 on Saturday, July 22, and posted a series of photos on Instagram documenting the festivities.

She showed off her party outfit -- a bright red strapless mini-dress covered in floral appliqués and fringe -- and posted numerous shots of the bash, with tons of guests and a huge birthday cake with sparklers.

Among the guests were Paris Hilton and Christina Aguilera. On Gomez's post featuring her party pictures, Hilton commented, "Happy Birthday beautiful! So much fun celebrating with you last night."

Gomez also shared photos on her Instagram story of what looked to be a private screening of the new "Barbie" movie. She was appropriately dressed in a hot pink feathered outfit and cowboy hat.

The singer also shared a snap of herself blowing out the candles on another cake.

In the caption, she encouraged fans to check out her mental health awareness fund, writing, "I am thankful for so much in my life and one of the things I am most thankful for is the work we've been able to do with the Rare Impact Fund through @Rarebeauty."

She continued, "Because of YOU we've been able to raise awareness and increase access to mental health services for young people. This is my true passion in life."

She added, "If you want to do something for my birthday, please donate to the Rare Impact Fund. If you have the means, consider donating to help us make a difference." She also included a donation link.