Dependent or not?

Hi - i've been struggling to determine if I can claim my son as a dependent or not.  He is a 21yo full time college student who lives at college, but my home is still a base for him.  He works and will have to file this year.  He does not cover more than 50% of his living and student costs through his work.  I am supporting him with health, auto, renters insurance, phone, and other expenses, but most of his school costs are covered by a 529 originally funded by his grandparents.  When I read the tests for a dependent, they are all "yes."

Relationship - child

Residence - my home, but maintains his own student apartment

Age - full time student under 23

Support - he cannot provide more than half his support through his income

Nationality - he is a US citizen

Marital Status - he is not married

 

I guess I am confused because while I support him, I am not personally supporting the other 50+%.  BTW, I became divorced after he turned 18 and my ex is not claiming him.

 

Can I still claim him as a dependent?  Thanks for looking!