I took advantage of this same Google Voice feature, and got myself a number with _7_ consecutive digits. So my phone number for an international caller is +1-234-567-xyzy.
It was very easy for my kids to memorize as they were growing up.
Sometimes, when I'm telling them my number for them to note down, people stop midway through until they realize I'm not really pranking them.
I'm sure people would not take me seriously if my number had all 10 digits in a sequence and started to repeat after that.