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Is 25 a prime number?

Prime Number Checker

Is 25 a prime or composite number?

Answer

Number 25 is not a Prime

25 = 5²

25 has 3 divisors — 1, 5 and 25; a prime has exactly two: 1 and itself. It is a perfect square.

Primes up to √25

5² = 25 ≤ 25 < 36 = 6², so it is enough to try primes up to 5

÷2 does not divide
÷3 does not divide
÷5 divides

25 ÷ 5 = 5 — 5 divides 25, so 25 is composite

Nearest primes: 23 and 29

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See Also

Factors of a Number - List all Factors and Factor Pairs of a Number
Prime Factorization - Prime Factorization Calculator
Prime Numbers List - List of all Prime Numbers - how many Prime numbers are between

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Is 25 a prime number? Is 25 a prime number? 25 is a composite number. Check if any number is prime or composite with our free online prime checker.

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Prime numbers list

Number	Is Prime
10	No: 2 × 5
11	Yes
12	No: 2² × 3
13	Yes
14	No: 2 × 7
15	No: 3 × 5
16	No: 2⁴
17	Yes
18	No: 2 × 3²
19	Yes
20	No: 2² × 5
21	No: 3 × 7
22	No: 2 × 11
23	Yes
24	No: 2³ × 3
25	No: 5²
26	No: 2 × 13
27	No: 3³
28	No: 2² × 7
29	Yes
30	No: 2 × 3 × 5
31	Yes
32	No: 2⁵
33	No: 3 × 11
34	No: 2 × 17
35	No: 5 × 7
36	No: 2² × 3²
37	Yes
38	No: 2 × 19
39	No: 3 × 13

FAQ

Is 25 a prime or composite number?

Number 25 is not a Prime

How many factors are in a number 25?

3

How to check if 25 is prime?

Divide 25 by the primes in order: 5² = 25 ≤ 25 < 36 = 6², so it is enough to try primes up to 5. The first one that divides it is 5: 25 ÷ 5 = 5, so 25 is composite.