Is 77 a prime number?

Prime Number Checker
Number

Is 77 a prime or composite number?

Answer

Number 77 is not a Prime

77 = 7 × 11

77 has 4 divisors — 1, 7, 11 and 77; a prime has exactly two: 1 and itself.

Primes up to √77

8² = 64 ≤ 77 < 81 = 9², so it is enough to try primes up to 8

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

77 ÷ 7 = 11 — 7 divides 77, so 77 is composite

Nearest primes: 73 and 79

Related Calculations

See Also

Prime numbers list

NumberIs Prime
62No: 2 × 31
63No: 3² × 7
64No: 2⁶
65No: 5 × 13
66No: 2 × 3 × 11
67Yes
68No: 2² × 17
69No: 3 × 23
70No: 2 × 5 × 7
71Yes
72No: 2³ × 3²
73Yes
74No: 2 × 37
75No: 3 × 5²
76No: 2² × 19
77No: 7 × 11
78No: 2 × 3 × 13
79Yes
80No: 2⁴ × 5
81No: 3⁴
82No: 2 × 41
83Yes
84No: 2² × 3 × 7
85No: 5 × 17
86No: 2 × 43
87No: 3 × 29
88No: 2³ × 11
89Yes
90No: 2 × 3² × 5
91No: 7 × 13

FAQ

Is 77 a prime or composite number?

Number 77 is not a Prime

How many factors are in a number 77?

4

How to check if 77 is prime?

Divide 77 by the primes in order: 8² = 64 ≤ 77 < 81 = 9², so it is enough to try primes up to 8. The first one that divides it is 7: 77 ÷ 7 = 11, so 77 is composite.

See Also