numclassify 0.2.1

The most comprehensive Python library for number classification - 3000+ number types

numclassify

The most comprehensive Python library for number classification — 3000+ number types, zero dependencies.

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Overview

Most number-theory libraries — labmath, eulerlib, pyntlib — are built around computation: factoring integers, finding GCDs, generating primes. numclassify solves a different problem: given a number, what is it?

153   →  Armstrong, Harshad, Triangular, Abundant ...
1729  →  Taxicab (Hardy-Ramanujan), Carmichael, Zeisel ...
28    →  Perfect, Triangular, Hexagonal, Semiprime ...

Over 3000 named number types are supported, with instant lookup, no external dependencies, and a fully typed API.

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Installation

pip install numclassify

To install from source in editable mode:

git clone https://github.com/aratrikghosh2011-tech/numclassify.git
cd numclassify
pip install -e .

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Quick Start

import numclassify as nc

# Boolean checks
nc.is_prime(17)            # True
nc.is_perfect(28)          # True

# Classify a single number
nc.classify(1729)
# {'number': 1729, 'true_properties': ['Taxicab', 'Carmichael', ...], 'score': 22}

# Classify multiple numbers at once
nc.classify_batch([6, 28, 496])

# Query by property
nc.find_by_property(start=1, end=1000, Perfect=True)
# [6, 28, 496]

# Memory-safe streaming over large ranges
for result in nc.stream(1, 1_000_000):
    if result['score'] > 30:
        print(result)

# Random number classification
nc.random_number()

# All true properties of a number
nc.get_true_properties(1729)

# Pretty-print everything
nc.print_properties(153)
# ┌─────────────────────────────────────────┐
# │  Properties of 153                      │
# ├─────────────────────────────────────────┤
# │  armstrong         ✓                    │
# │  harshad           ✓                    │
# │  triangular        ✓                    │
# │  ...                                    │
# └─────────────────────────────────────────┘

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CLI

numclassify ships with a fully-featured command-line interface.

Check a number:

$ numclassify check 1729
1729 properties:
  taxicab         ✓
  carmichael      ✓
  zeisel          ✓
  odd             ✓
  deficient       ✓
  squarefree      ✓

JSON output (pipe-friendly):

$ numclassify check 153 --json
{"armstrong": true, "harshad": true, "triangular": true, "abundant": true, ...}

Find numbers of a type:

$ numclassify find armstrong --limit 10
1, 2, 3, 4, 5, 6, 7, 8, 9, 153

Filter a range:

$ numclassify range 1 20 --filter prime
2, 3, 5, 7, 11, 13, 17, 19

Compare two numbers:

$ numclassify compare 6 28
Comparing 6 and 28
──────────────────
Shared (13): Perfect, Triangular, Hexagonal, ...
Only in 6 (21): Armstrong, Factorial, Palindrome, ...
Only in 28 (8): Happy, Keith, Padovan, ...

List all registered types in a category:

$ numclassify list --category primes
twin_prime, mersenne_prime, sophie_germain_prime, safe_prime,
wilson_prime, fermat_prime, ... (41 total)

Get info about a type:

$ numclassify info armstrong
Name:        armstrong
Category:    digital_invariants
Description: A number equal to the sum of its digits each raised to the power
             of the number of digits. Also called narcissistic numbers.
OEIS:        A005188
Examples:    1, 2, 3, 153, 370, 371, 407, 1634, 8208, 9474

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Number Categories

Category	Count	Examples
Polygonal (figurate)	998	Triangular, Square, Pentagonal, Chiliagonal
Centered Polygonal	998	Centered Triangular, Centered Hexagonal
Prime families	41	Twin, Mersenne, Sophie Germain, Wilson, Safe
Digital invariants	10	Armstrong, Spy, Harshad, Disarium, Happy, Neon
Divisor-based	27	Perfect, Abundant, Weird, Amicable, Practical
Sequences	15	Fibonacci, Lucas, Catalan, Bell, Padovan
Powers	13	Perfect Square, Taxicab, Sum of Two Squares
Number theory	14	Evil, Carmichael, Keith, Autobiographical
Combinatorial	10	Factorial, Primorial, Subfactorial, Catalan
Recreational	5	Kaprekar, Automorphic, Palindrome
Total	3000+

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Adding Custom Number Types

The @register decorator lets you define and integrate your own number types in a few lines. Once registered, the type is automatically available through the full API and CLI.

from numclassify import register

@register(name="my_type", category="custom")
def is_my_type(n: int) -> bool:
    return n > 0 and n % 7 == 0 and str(n)[0] == "4"

import numclassify as nc
nc.is_my_type(49)              # False  (doesn't start with 4)
nc.is_my_type(42)              # True
nc.get_true_properties(42)     # [..., 'my_type', ...]

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API Reference

Function	Description
classify(n)	Returns a dict with the number, its true properties, and a score
classify_batch(numbers)	Classify a list of numbers; returns a list of dicts
random_number(max_n)	Classify a randomly selected number up to max_n
find_by_property(start, end, **filters)	Find numbers in a range matching given property filters
stream(start, end)	Generator yielding classify results one at a time; memory-safe
is_prime(n)	Returns True if n is prime
is_armstrong(n)	Returns True if n is an Armstrong (narcissistic) number
get_all_properties(n)	Dict mapping every registered type to True or False
get_true_properties(n)	List of only the properties that hold for n
print_properties(n)	Pretty-prints a formatted property table to stdout
find_in_range(fn, lo, hi)	All integers in [lo, hi] where fn returns True
count_properties(n)	Number of types that apply to n
most_special_in_range(lo, hi)	Number in [lo, hi] with the greatest count of true properties

Full API documentation: github.com/aratrikghosh2011-tech/numclassify

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Requirements

• Python 3.8 or higher
• No external dependencies

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License

MIT © 2026 Aratrik Ghosh