Number 07907 393864 is potentially valid
Ofcom records show that numbers starting 079073 are allocated to Telefonica UK 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 2006.
The correct way to write the telephone number 07907393864 is 07907 393864
For more information on tariffs and usage of numbers starting 07 please visit the page on 07 numbers