Default GW public IP pinging from outside but router's public IP not

[aammar@npr.org]

Question is one of my cisco routers is directly with ISP. we have static IP configured on router assigned by ISP. Now the thing is from outside network, I can ping my ISP's gateway IP but I can't ping router's public IP. When I logged in through console in my router, I can't ping ISP's gateway IP and can't ping google DNS. Any recommendations what could be the reason?

I thought it might ISP issue but since its gateway IP pinging from outside so it puts me in doubt. Routers logs are not showing anything 

[ammahend]

on your router check if you have a default route or default gateway pointing to ISP IP to return traffic. 

[M02@rt37]

Hello aammar@npr.org,

You say "we have static IP configured on router assigned by ISP". 

Is it a default IP route pointing ISP box/router interface?

[aammar@npr.org]

Yes

[MHM Cisco World]

can  I see static route