Number 070 8970 5208 is potentially valid
Ofcom records show that numbers starting 070897 are allocated to Cheers International Sales Limited. Note that due to number portability if an individual number has moved to a different operator this information is not publicly available.
Ofcom's last recorded change for this number range was February 2008.
The correct way to write the telephone number 07089705208 is 070 8970 5208
For more information on tariffs and usage of numbers starting 07 please visit the page on 07 numbers