Guides
There are 25 prime numbers between 1 and 100. Here is the full list, how it is generated, and how to use it as a quick reference.
Prime numbers 1 to 100
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97 — 25 primes in total.
How the chart is built
The Sieve of Eratosthenes crosses out multiples of each prime (2, 3, 5, 7) up to 100. Whatever survives is prime.
Patterns to notice
2 is the only even prime. After 5, every prime ends in 1, 3, 7 or 9. Primes thin out as numbers grow but never stop.
How to use the chart
It speeds up prime factorization (you trial-divide only by these primes) and lets you check small numbers at a glance. To verify any number — in or beyond the list — use the Prime Number Checker.
Beyond 100
The same sieve extends to any limit. For a single number, trial division up to its square root is faster — see how to check if a number is prime.
Key takeaways
- There are 25 primes from 1 to 100.
- 2 is the only even prime.
- After 5, primes end in 1, 3, 7 or 9.
- The sieve builds the chart by crossing out multiples.
Prime Number Checker
Verify whether any number is prime, with nearest primes and smallest divisor.
Open the Prime Number CheckerFrequently asked questions
How many prime numbers are there from 1 to 100?
There are 25 prime numbers between 1 and 100.
What is the largest prime under 100?
97 is the largest prime number below 100.
Is 2 really prime?
Yes — 2 is prime and is the only even prime number; every other even number is divisible by 2.
The LCM Calculator Team
Math educators and engineers building free, accurate calculators with step-by-step solutions, visual diagrams and AI insights.