Twelve is an even number.
I forgot his phone number.
What number bus do I take?
I forgot your phone number.
Give me your telephone number.
I forget your telephone number.
Does she know your phone number?
I seem to have the wrong number.
She asked him if he knew my telephone number.
Tom wrote Mary's phone number in his little black book.
If he had known her phone number, he could have called her up.