It's funny that the most massive black hole known is called TON 618. In fact its mass is about 10³⁸ tonnes. Its event horizon is roughly 400 billion kilometers - over forty times the diameter of Neptune’s orbit. It sits proudly at the center of a distant galaxy.
Because it's so huge, you could fall into it without being ripped apart as you went through the event horizon.
And its surface gravity is *less* than most black holes! The surface gravity is the force per mass registered by a stationary faraway observer holding the mass right above the horizon via a long string. Surprisingly, this is inversely proportional to the black hole's mass.
For a 3-solar-mass black hole, the surface gravity is half a trillion times the surface gravity on Earth - half a trillion g's.
For the black hole at the center of the Galaxy, it's 3 million g's.
For TON 618, it's just 230 g's. Still damn strong, but much less!
The concept of surface gravity for black holes is a bit weird, and I didn't explain it carefully - but it does make sense, and it's important. The temperature of a black hole is proportional to its surface gravity!
It's explained more here: