Is my cat a birman?

Helloo! I have had my cat for a long time and he had multiple owners before. I was wondering what breed of cat he is, because my partner (it's actually his cat) said he is a birman. I was looking at birman cats on the internet and it says they should have white feet, but mine doesn't. I suspected he may be a mix between a birman and a siamese. Any guesses?