Mortgage rate too low?

Just been doing some sums & I think I'm only paying around 1.4% interest per year on my mortgage.

I owe around £72000 and am getting a monthly interest charge of £84.

I can't find any lenders offering anything like this rate (my current lenders website cheapest rates are more than double this).

Anyone know if this is likely to be a mistake on the lenders side? (or my calculation?) - or is this a typical amount of interest to pay.

Thanks for any advice!