Kim Kardashian West proves that age is just a number in her new bikini pics. The mother of four took to social media on Monday to show off her impressive physique in a skimpy thong two-piece, which she accessorized with large shades and a bandana wrapped around her head.

In the images, Kim shows off her hourglass figure from all angles, captioning the post, “This is 40!”

A source previously told ET that Kanye West’s wife brought her family and friends to an island on private planes last Wednesday to celebrate her milestone birthday.

The new images appear to be from this exclusive tropical getaway. The reality star already rang in her 40th birthday last week, sharing her epic family surprise party on a special episode of Keeping Up With the Kardashians.

The event was organized by celebrity party planner Mindy Weiss and highlighted all of Kim’s past birthday parties, starting with her first birthday with ponies to the Tao nightclub soirees she enjoyed in her 30s. Her sisters got in on the fun by choreographing a dance number her friends previously performed at her 10th birthday.

Prior to the surprise party, Kim opened up during the episode about her pre-COVID plans for her big day.

She had initially been planning a “Wild, Wild Mrs. West” party in Wyoming and wanted to wear a robotic couture piece from designer Thierry Mugler.