The Teenage Dream star, who married the comedian on 23rd October 2010, is apparently 'dreading' the date after splitting with Brand after just 14 months of marriage.
An insider told The Sun: "Katy has been dreading October 23 for weeks now, and has been trying to think of ways to turn it into something positive.
"It's her birthday two days later and the last thing she wanted to do was spend that week depressed and miserable, which would then mean not doing anything to celebrate her birthday."
They continued: "Her pals have been persuading her to have a huge party or go to Vegas for a few days, but Katy decided on throwing a small gathering at her home.
"She has decided to call it her 'divorce party', and it will be a day of doing what she loves with her favourite people."
K-Pez has been romantically linked with singer/songwriter John Mayer since her break-up from Russell, with Brand being spotted with a number of women, including Geri Halliwell.
Last week, Perry was left 'devastated' following the death of her ex-boyfriend Johnny Lewis - who was found dead at his Los Angeles home on Wednesday (26th September).
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