Numbers /21,525
How rare is 21,525?
21,525 scores 472 and sits in the Extreme tier — 1 in 265 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 0.38% means that proportion of supported numbers scores at least this high. Every exact number has the same chance of being rolled. Same-length rank keeps the score and compares only numbers with 5 digits, including ties. 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.
Its binary form reads the same both ways.
Representation · signal frequency
This number's digits add up to an uncommon total.
Arithmetic · signal frequency
This number uses an uncommon count of distinct digits.
Repetition · signal frequency
Every comparison strictly alternates between rising and falling.
Sequence · signal frequency
Divisible by the sum of its digits.
Arithmetic · signal frequency
Two different digits each appear twice.
Repetition · signal frequency
Strongest signal: Binary palindrome. It appears in 1,998 supported numbers and contributes +179 after correlation decay.
Why is 21,525 unusual? Only 0.38% of the 1,000,001 supported numbers receive an equal or higher rarity score. This number falls in the Extreme 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
One digit away
One digit, +35 points.
Your number
21,525
Extreme · Top 0.38%
Position 3: 5 → 0 · +35 points.
Gained: Perfect square, Digit sum 10, Descending segment, 4 distinct digits, Repeated digit.
44 legal neighbours · same digit length · no leading zeros. This describes an alternative number, not the odds of your next roll.
Explore & share this near miss →Similar interesting numbers
Explore a shared pattern, a comparable score, or a mathematical relationship. Every link explains its connection to 21,525.
Shared patterns
Same length, nearby scores
Patterns in this number
Each of these has its own page explaining how common the pattern is and why.
Double Pair Numbers
A double pair has two different digits appearing twice each, like 3388 or 271721. It is the digit equivalent of two pair in poker.
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.
Binary Palindromes
Written in base two, these numbers read the same forwards and backwards. 9 is 1001, and 585 is 1001001001.