I type the phone number into any search engine. In that way if it's a real number, the real organization usually comes up in the search. Also contained in the search are numerous resources that keep track of scam numbers, etc
It's not always possible to tell if someone is calling you from a genuine number or a spoofed number. I have received calls before where the scammer used a number of a genuine business to try to scam me. Googling the number might be helpful but also might be a waste of time. They have been known to use phone numbers of random customers who are unaware their number was spoofed.
