No, it isn't. Not yet, anyway.
E62 is an ARM based device, and there are ARM based Linux system abound, but it's not as simple as merely "installing" a new OS. Your device runs Symbian Series 60, Third Edition (or S60v3 for short). The firmware should be hackable - I believe even the latest S60v3 firmwares can be hacked using HelloX. If you're interested, head on over to Symbian-Freak.com (I'm there too, by the way).