Math & Numbers
Prime Number Checker
Check if a number is prime and generate a list of primes up to any value.
Enter any number to instantly find out if it's prime, see its factors if it's composite, and discover the nearest prime numbers above and below it. Great for math students, number theory enthusiasts, and quick verifications.
Features
Prime Test
Instantly determine if a number is prime or composite.
Factor List
For composite numbers, see all prime factors.
Nearest Primes
Find the closest prime numbers above and below your input.
Instant Result
Check any number in milliseconds.
How to Check
- Enter any positive integer in the input field.
- The result appears instantly: Prime or Composite.
- For composite numbers, the prime factorization is shown.
FAQ
Is 1 a prime number?▾
No. By definition, prime numbers must have exactly two distinct divisors (1 and themselves). The number 1 has only one divisor.
What is the largest prime this tool can check?▾
The tool uses efficient algorithms and can handle very large numbers, though extremely large inputs may take a moment.
Prime Number Facts
- 2 is the only even prime number.
- There are infinitely many prime numbers (proven by Euclid ~300 BC).
- The largest known prime (as of 2024) has over 41 million digits.
More Math & Numbers
Percentage Calculator
Calculate percentages, changes, and find what percent one number is of another
Unit Converter
Convert length, weight, temperature, and more
Random Number Generator
Generate random numbers within any range you set
BMI Calculator
Calculate your Body Mass Index with metric or imperial units
Tip Calculator & Bill Splitter
Calculate tip amount and split the bill among any group
Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal
Roman Numeral Converter
Convert numbers to Roman numerals and back (1–3999)
Compound Interest Calculator
Calculate compound interest with year-by-year breakdown
Discount Price Calculator
Find final price, discount percentage, or original price
Statistics Calculator
Calculate mean, median, mode, standard deviation, and more
Loan & Mortgage Calculator
Calculate monthly payments, total interest, and full amortization schedule
Aspect Ratio Calculator
Calculate missing width or height from an aspect ratio. Supports 16:9, 4:3, and custom ratios
GPA Calculator
Calculate semester and cumulative GPA from courses, grades, and credit hours
Calorie & BMR Calculator
Calculate your BMR and daily calorie needs based on activity level and goal
Loan EMI Calculator
Calculate monthly EMI, total interest, and repayment for any loan.