Numbers /1,638
How rare is 1,638?
1,638 scores 694 and sits in the Singular tier — 1 in 1,828 of all supported numbers score this high or higher. Everything below is computed from a complete analysis of all 1,000,001 numbers in range.
RNGdle.net’s own rarity score. Top 0.05% means that proportion of supported numbers scores at least this high. Every exact number has the same chance of being rolled. How this differs from EP · Badge guide
These notes make the number easy to read, but they add no score unless a separately counted rarity signal appears below.
Every hexadecimal digit is identical.
Representation · signal frequency
One of 9,000 four-digit numbers in range.
Range · signal frequency
This number's digits add up to an uncommon total.
Arithmetic · signal frequency
Digits strictly alternate between odd and even.
Sequence · signal frequency
This number uses an uncommon count of distinct digits.
Repetition · signal frequency
Divisible by the sum of its digits.
Arithmetic · signal frequency
Every comparison strictly alternates between rising and falling.
Sequence · signal frequency
Strongest signal: Hex repdigit. It appears in 59 supported numbers and contributes +281 after correlation decay.
Why is 1,638 unusual? Only 0.05% of the 1,000,001 supported numbers receive an equal or higher rarity score. This number falls in the Singular tier. Scoring is grounded in the exact frequency of each detected trait — rarer traits carry more information and contribute more to the score.
Algorithm version 1.1.0
Patterns in this number
Each of these has its own page explaining how common the pattern is and why.
Alternating Odd and Even Digits
Odd, even, odd, even — or the reverse — all the way through, as in 385274 or 1614. The digits themselves are free; only their parity is constrained.
Zigzag Digit Numbers
Every comparison changes direction: up, down, up, down — or the reverse. In 792619 the path is 7 < 9 > 2 < 6 > 1 < 9.
Harshad Numbers
A Harshad — or Niven — number is divisible by the sum of its own digits. 18 works because 1 + 8 = 9 and 18 ÷ 9 = 2.
Hexadecimal Repdigits
In base sixteen every digit is the same: 255 is FF, 4095 is FFF, and 43690 is AAAA.