GP didn't say odd, or at least not numerically odd, but rather "ending in impossible digits".

Floats have varying precision, not uniform. The closer the number is to zero, the more precision it has. There's a point where the precision is so low that it only covers whole numbers, and then a point after that where the precision is less than whole numbers.

Given the context of pointers, it's quite possible that they were large enough to reach that less-than-whole-number-precision range.

EDIT: For 32-bit floats, that's apparently any number above 16,777,216. Which seems surprisingly small to me. For 64-bit doubles that goes to 9,007,199,254,740,992.

https://blog.demofox.org/2017/11/21/floating-point-precision