Is 138 a prime number?

Prime Number Checker
Number

Is 138 a prime or composite number?

Answer

Number 138 is not a Prime

138 = 2 × 3 × 23

138 has 8 divisors — 1, 2, 3, 6, 23, 46, 69 and 138; a prime has exactly two: 1 and itself.

Primes up to √138

11² = 121 ≤ 138 < 144 = 12², so it is enough to try primes up to 11

  • ÷2 divides

138 ÷ 2 = 69 — 2 divides 138, so 138 is composite

Nearest primes: 137 and 139

Related Calculations

See Also

Prime numbers list

NumberIs Prime
122No: 2 × 61
123No: 3 × 41
125No: 5³
126No: 2 × 3² × 7
127Yes
128No: 2⁷
129No: 3 × 43
130No: 2 × 5 × 13
131Yes
132No: 2² × 3 × 11
133No: 7 × 19
134No: 2 × 67
135No: 3³ × 5
136No: 2³ × 17
137Yes
138No: 2 × 3 × 23
139Yes
140No: 2² × 5 × 7
141No: 3 × 47
142No: 2 × 71
143No: 11 × 13
144No: 2⁴ × 3²
145No: 5 × 29
146No: 2 × 73
147No: 3 × 7²
148No: 2² × 37
149Yes
150No: 2 × 3 × 5²
151Yes
152No: 2³ × 19

FAQ

Is 138 a prime or composite number?

Number 138 is not a Prime

How many factors are in a number 138?

8

How to check if 138 is prime?

Divide 138 by the primes in order: 11² = 121 ≤ 138 < 144 = 12², so it is enough to try primes up to 11. The first one that divides it is 2: 138 ÷ 2 = 69, so 138 is composite.

See Also