How should I write my mobile telephone number in an email?

I want to send something like

>Hi,

>Following is my mobile number 0000 000 000

>Thanks

or

>Hi, 

>My mobile number is 000 000 0000

>Please feel free to call me whenever needed.

>Thanks

Should I use spaces in the number? Or write it in one single block 0000000000? Or some other way?