I think it’s 1384939384$3
The theoretical probability of (for example) rolling 5 ones is 1/(6^5) or approximately 0.013%. Because it doesn't matter which number we get five of we can multiply it by 6 to get 1/(6^5) or approximately 0.077%.
By the binomial theorem,

Each term containing a factor 6 is divisible by 3, since 3 divides 6. The remaining 1 and 2 sum to 3, which is also divisible by 3.