Most commonly used numbers: statistics, psycholinguistics, and Benford's Law

Introduction: The number as a unit of information and a cultural marker

The question of the frequency of numbers seems simple, but its analysis lies at the intersection of mathematical statistics, perception psychology, linguistics, and information theory. It is important to distinguish between the natural frequency of occurrence of numbers in numerical data in the real world and their subjective frequency in human practice (in numbers, prices, elections). The most surprising is that these distributions are not random or uniform, but follow deep regularities that are important for data analysis, fraud detection, and understanding cognitive distortions.

1. Benford's Law: unexpected asymmetry in the world of numbers

The most powerful and counter-intuitive fact about the frequency of numbers is described by Benford's Law (the first digit law). It states that in many natural sets of numerical data (from electricity bills and mountain heights to molecular weights and stock market quotations), the probability that the first significant digit (from 1 to 9) will be equal to d is calculated by the formula: P(d) = log₁₀(1 + 1/d).

This gives the following distribution of probabilities for the first digit:

1 appears approximately in 30.1% of cases.

2 — about 17.6%.

3 — about 12.5%.

Then the frequency decreases: 9 occurs only in 4.6% of cases.

Reason: The Law works for data that are distributed over many orders of magnitude (from units to millions) and describe processes of growth or multiplication. For example, the population of cities, stock prices, lake areas. The number 1 leads because to move from 1 to 2 the value must increase by 100%, while from 8 to 9 — only by 12.5%. The system “sticks” to numbers starting with 1 longer.

Application: Tax and financial authorities around the world use Benford's Law to detect suspicious reports and falsified data, as a person inventing numbers intuitively tends to an even distribution (about 11% on each digit), which is statistically unnatural.

2. Subjective preferences: favorite numbers of a person

When people choose numbers consciously (for PIN codes, lottery tickets, “lucky numbers”), psychological and cultural factors come into play. Research shows stable preferences:

The number 7 is the absolute leader in Western and many other cultures. Its sacred status (7 days of the week, 7 wonders of the world, 7 notes) makes it the most “attractive” and often chosen.

The number 3 is also extremely popular due to its cultural significance (trinity, three wishes, triad). It is perceived as harmonious and complete.

The numbers 1, 2, 5, 8, 9 have average popularity. 5 and 10 are often chosen due to the convenience of rounding.

The least favorite numbers: 0 (associated with emptiness, failure) and 4 (in Eastern Asian cultures — homophone of the word “death”, but even in the West it seems “unlucky”). 6 may also be less popular outside the religious context.

Interesting fact: Research on millions of selected user PIN codes showed that “1234” remains the most popular PIN code in the world (more than 10% of all), which eloquently speaks of neglecting security in favor of simplicity and patterned thinking.

3. Economics and marketing: the magic of numbers 9 and 5

In pricing, the distribution of numbers is artificially distorted in favor of certain values.

Pricing strategy (“charm pricing”): Prices ending in .99 or .95 dominate in retail trade. Psychologically, the price of $4.99 is perceived as closer to $4 than to $5 (the effect of the left digit). According to studies, up to 60% of all retail prices end in the digit 9.

The number 5: Prices ending in .50 are also very popular, especially for goods in the middle and high price range, as they create the impression of quality and a reasonable compromise.

“Round numbers” (0): Used for positioning luxury goods or for simple, basic offers ($200, $1000), creating a sense of transparency, quality, and the absence of manipulation.

4. Linguistic aspect: Zipf's Law for numerals

If we consider numbers as words (numerals), then here general linguistic laws of frequency apply. Zipf's Law states that in natural language, the frequency of any word is inversely proportional to its rank in the frequency list. Applied to numerals:

The most frequent in speech will be the smallest numbers: one, two, three. They are used not only for counting, but also in idioms, as pronouns (“one of us”), for indicating an indefinite quantity (“one person said”).

Frequency decreases sharply with increasing numerical value. Words like seventy or ninety are encountered several times less than ten or twenty.

5. Informatics and numeral systems: dominance of 0 and 1

In the digital age, the “landscape” of the use of numbers has fundamentally changed. The foundation of all digital technology is a binary code consisting of only two “digits”: 0 and 1. Thus, in the world of information flows and data processing, 0 and 1 are absolutely dominant symbols, and their ratio can be a key parameter for data compression or cryptanalysis.

Example: In IPv4 addressing, which is the foundation of the Internet, the most frequently encountered in the lower octets (the last number in the IP address, for example, 192.168.1.X) are 0 (denotes the network), 1 (often assigned to the default router), and 255 (broadcast address). This demonstrates how technical protocols create their own, unnatural peaks in the distribution of numbers.

Conclusion: Numbers as a mirror of reality and reason

The distribution of frequently used numbers is not an artifact, but a deep reflection of the structure of our physical reality, economic behavior, psychological characteristics, and technological progress.

In the world of phenomena, Benford's Law prevails with the leading unit.

In the world of human choice, seven and three reign as cultural archetypes.

In the world of the market, nine dominates.

In the world of information, zero and one are fundamental.

Thus, in answering the question “Which numbers are used most often?”, it is necessary to always clarify the context: objective data or subjective choice, natural processes or social constructs. The study of this frequency is a powerful tool for statisticians, economists, psychologists, and digital security experts, revealing hidden patterns and anomalies in various aspects of life.

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