Is 221 a prime number?

Prime Number Checker
Number

Is 221 a prime or composite number?

Answer

Number 221 is not a Prime

221 = 13 × 17

221 has 4 divisors — 1, 13, 17 and 221; a prime has exactly two: 1 and itself.

Primes up to √221

14² = 196 ≤ 221 < 225 = 15², so it is enough to try primes up to 14

  • ÷2 does not divide
  • ÷3 does not divide
  • ÷5 does not divide
  • ÷7 does not divide
  • ÷11 does not divide
  • ÷13 divides

221 ÷ 13 = 17 — 13 divides 221, so 221 is composite

Nearest primes: 211 and 223

Related Calculations

See Also

Prime numbers list

NumberIs Prime
204No: 2² × 3 × 17
205No: 5 × 41
206No: 2 × 103
207No: 3² × 23
208No: 2⁴ × 13
209No: 11 × 19
210No: 2 × 3 × 5 × 7
211Yes
213No: 3 × 71
214No: 2 × 107
215No: 5 × 43
216No: 2³ × 3³
217No: 7 × 31
219No: 3 × 73
220No: 2² × 5 × 11
221No: 13 × 17
222No: 2 × 3 × 37
223Yes
225No: 3² × 5²
226No: 2 × 113
227Yes
229Yes
231No: 3 × 7 × 11
232No: 2³ × 29
233Yes
234No: 2 × 3² × 13
235No: 5 × 47
237No: 3 × 79
238No: 2 × 7 × 17
239Yes

FAQ

Is 221 a prime or composite number?

Number 221 is not a Prime

How many factors are in a number 221?

4

How to check if 221 is prime?

Divide 221 by the primes in order: 14² = 196 ≤ 221 < 225 = 15², so it is enough to try primes up to 14. The first one that divides it is 13: 221 ÷ 13 = 17, so 221 is composite.

See Also