14 is the product of 2 and 7, and the smallest number whose two prime factors are the first and fourth primes. It sits in a run of three consecutive composites, 14, 15 and 16, which is the sort of gap that becomes routine higher up. It is not prime. 14 = 2 × 7, so it has 4 divisors rather than two, ...
WORTH TRYING
14 IS
NOT PRIME
SMALLEST FACTOR
2
14 = 2 × 7
Prime factorisation
2 × 7
Number of divisors
4
Sum of divisors
24
Totient φ(n)
6
Previous prime
13
Next prime
17
FACTOR BREAKDOWN
PRIME
POWER
CONTRIBUTES
2
1
2
7
1
7
STEPS
Trial-divide 14 by every prime up to √14 ≈ 3 — beyond that a factor would have a partner below it
The smallest prime divisor is 2, so 14 is composite
Full factorisation: 2 × 7
14 is NOT prime
SIEVE OF ERATOSTHENES
Two thousand years old and still the fastest way. Take the first uncrossed number, 2, and strike out every multiple of it. Move to the next survivor, 3, and repeat. Each pass can start at the square of its prime, because anything smaller was already struck by a smaller factor — which is why the passes get shorter and stop entirely once the prime exceeds √100. Whatever survives is prime. Your number 14 is outlined in gold.
HOW MANY PRIMES BELOW x — AND WHAT THE THEORY PREDICTS
Actual count against x ÷ ln x. At x = 10 the estimate overshoots slightly; from 100 upward it runs low, and from 1,000 onward the gap narrows steadily — a ratio of 1.16 at a thousand down to 1.10 at a hundred thousand. That it tends to 1 at all is the Prime Number Theorem, and how slowly it does so is why the proof took a century to find.
Proved, not guessed. Primality here uses a deterministic Miller–Rabin test with a fixed witness set that is proven correct for every number this page accepts, so a result of PRIME is a proof rather than a probability. Ranges are sieved up to 200,000; single numbers are tested up to 4,503,599,627,370,495.
Live simulation · drawn to scale · updates as you type
The answer is already on screen: 14 is not prime, because 14 = 2 × 7. Nothing needs typing — this page opens the calculator with 14 loaded.
Read the STEPS panel to see the reasoning: the smallest prime divisor of 14 is 2, which is enough to settle it, and the full factorisation 2 × 7 follows.
Check the six tiles for the derived quantities — divisor count, divisor sum, Euler's totient and the primes either side. All of them come from the factorisation rather than from separate searches.
Type a different number to carry on, or switch to RANGE to sieve a whole interval at once and see how the primes thin out as the numbers grow.
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Last updated: July 28, 2026 · Formula verified · Deterministic Miller–Rabin, so a result of PRIME is proven rather than probable · Eagle-eyed accuracy for every calculation.