Issue while trying to convert date time to number in c# from php

Question

I was trying to convert below lines of php code into c#

$long = strtotime('2022-04-30 21:47:00');
date('Y-m-d H:i:s', $long);

echo $long;

Output is 1651348020 which is a 10 digit number. This works fine for me.

Then I tried to write code in c# which was below...

DateTime.Now.Ticks

Output was a 20 digit number.

Can you please suggest how to get 10 digit number?