Number Sequence Analysis: Find the Outlier in 6, 16, 86, 56, 64

To solve this problem, let's look at the intrinsic properties of each number:

• Number $6$: Single digit, so there's no digit relationship to analyze.
• Number $16$: Sum of digits is $1 + 6 = 7$.
• Number $86$: Sum of digits is $8 + 6 = 14$.
• Number $56$: Sum of digits is $5 + 6 = 11$.
• Number $64$: Sum of digits is $6 + 4 = 10$.

On examining these numbers further for a pattern, one might think about considering a multiplication operation:

• Number $16$: Product of digits is $1 \times 6 = 6$.
• Number $86$: Product of digits is $8 \times 6 = 48$.
• Number $56$: Product of digits is $5 \times 6 = 30$.
• Number $64$: Product of digits is $6 \times 4 = 24$.

Evaluating these products and observing, an interesting quirk for some numbers: If each tens digit aligns with or relates to a another manner (e.g.,which when digits are concatenated, appear to flow toward a pattern observed in mathematical bases), we find each number ends inconsistently.

Ultimately recognizing a number contrary to others, the structural count of being a multiple, managed by intrinsic value: $64$ which relationally forms title of other sequences. Thus, when breaking numerical properties, $64$ emerges asynchronously as the odd one out.

Therefore, the number that is the odd one out is $64$.