Numbers /7
How rare is 7?
7 scores 1,305 and sits in the Singular tier — 1 in 142,857 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 <0.01% 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.
Only 10 of the 1,000,001 supported numbers have one digit.
Range · signal frequency
Equal to 2^k − 1, so its binary form is all ones.
Representation · signal frequency
This number uses an uncommon count of distinct digits.
Repetition · signal frequency
This number's digits add up to an uncommon total.
Arithmetic · signal frequency
Divisible only by 1 and itself.
Factorization · signal frequency
Its binary form reads the same both ways.
Representation · signal frequency
Divisible by the sum of its digits.
Arithmetic · signal frequency
Iterating the sum of squared digits reaches 1.
Arithmetic · signal frequency
Strongest signal: Single-digit number. It appears in 10 supported numbers and contributes +332 after correlation decay.
Why is 7 unusual? Only <0.01% 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.
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.
Happy Numbers
Square each digit, add them up, repeat. If you eventually reach 1 the number is happy; if not, you fall into a cycle. 19 → 82 → 68 → 100 → 1.
Prime Numbers
A prime has no divisors other than 1 and itself. They are the building blocks every other number is assembled from.
Binary Palindromes
Written in base two, these numbers read the same forwards and backwards. 9 is 1001, and 585 is 1001001001.
Binary Repunits
These are the numbers one short of a power of two — 3, 7, 15, 31, 63, 1023 — whose binary form is nothing but ones.