🍀 isPrime

To check a number is a prime

Prime Number Tester

Enter a number

Is 13 a prime?

Prime

The Code

function isPrime(n) {
  if (typeof(n)==='number') {
    for (let i=2;i<=Math.sqrt(n);i++) {
      if (n%i===0) {
        return false
      }
    }
    return n>1
  }
  return false
}

Usage

isPrime(13) // true

isPrime(17) // true

isPrime(10) // false

Examples

isPrime(1)

false

1 is Prime

isPrime(2)

true

2 is Prime

isPrime(3)

true

3 is Prime

isPrime(4)

false

4 is Prime

isPrime(5)

true

5 is Prime

isPrime(6)

false

6 is Prime

isPrime(7)

true

7 is Prime

isPrime(8)

false

8 is Prime

isPrime(9)

false

9 is Prime

isPrime(10)

false

10 is Prime

isPrime(11)

true

11 is Prime

isPrime(12)

false

12 is Prime

isPrime(13)

true

13 is Prime

isPrime(14)

false

14 is Prime

isPrime(15)

false

15 is Prime

isPrime(16)

false

16 is Prime

isPrime(17)

true

17 is Prime

isPrime(18)

false

18 is Prime

isPrime(19)

true

19 is Prime

isPrime(20)

false

20 is Prime

isPrime(21)

false

21 is Prime

isPrime(22)

false

22 is Prime

isPrime(23)

true

23 is Prime

isPrime(24)

false

24 is Prime

isPrime(25)

false

25 is Prime

isPrime(26)

false

26 is Prime

isPrime(27)

false

27 is Prime

isPrime(28)

false

28 is Prime

isPrime(29)

true

29 is Prime

isPrime(30)

false

30 is Prime

isPrime(31)

true

31 is Prime

isPrime(32)

false

32 is Prime

isPrime(33)

false

33 is Prime

isPrime(34)

false

34 is Prime

isPrime(35)

false

35 is Prime

isPrime(36)

false

36 is Prime

isPrime(37)

true

37 is Prime

isPrime(38)

false

38 is Prime

isPrime(39)

false

39 is Prime

isPrime(40)

false

40 is Prime

isPrime(41)

true

41 is Prime

isPrime(42)

false

42 is Prime

isPrime(43)

true

43 is Prime

isPrime(44)

false

44 is Prime

isPrime(45)

false

45 is Prime

isPrime(46)

false

46 is Prime

isPrime(47)

true

47 is Prime

isPrime(48)

false

48 is Prime

isPrime(49)

false

49 is Prime

isPrime(50)

false

50 is Prime

isPrime(51)

false

51 is Prime

isPrime(52)

false

52 is Prime

isPrime(53)

true

53 is Prime

isPrime(54)

false

54 is Prime

isPrime(55)

false

55 is Prime

isPrime(56)

false

56 is Prime

isPrime(57)

false

57 is Prime

isPrime(58)

false

58 is Prime

isPrime(59)

true

59 is Prime

isPrime(60)

false

60 is Prime

isPrime(61)

true

61 is Prime

isPrime(62)

false

62 is Prime

isPrime(63)

false

63 is Prime

isPrime(64)

false

64 is Prime

isPrime(65)

false

65 is Prime

isPrime(66)

false

66 is Prime

isPrime(67)

true

67 is Prime

isPrime(68)

false

68 is Prime

isPrime(69)

false

69 is Prime

isPrime(70)

false

70 is Prime

isPrime(71)

true

71 is Prime

isPrime(72)

false

72 is Prime

isPrime(73)

true

73 is Prime

isPrime(74)

false

74 is Prime

isPrime(75)

false

75 is Prime

isPrime(76)

false

76 is Prime

isPrime(77)

false

77 is Prime

isPrime(78)

false

78 is Prime

isPrime(79)

true

79 is Prime

isPrime(80)

false

80 is Prime

isPrime(81)

false

81 is Prime

isPrime(82)

false

82 is Prime

isPrime(83)

true

83 is Prime

isPrime(84)

false

84 is Prime

isPrime(85)

false

85 is Prime

isPrime(86)

false

86 is Prime

isPrime(87)

false

87 is Prime

isPrime(88)

false

88 is Prime

isPrime(89)

true

89 is Prime

isPrime(90)

false

90 is Prime

isPrime(91)

false

91 is Prime

isPrime(92)

false

92 is Prime

isPrime(93)

false

93 is Prime

isPrime(94)

false

94 is Prime

isPrime(95)

false

95 is Prime

isPrime(96)

false

96 is Prime

isPrime(97)

true

97 is Prime

isPrime(98)

false

98 is Prime

isPrime(99)

false

99 is Prime

isPrime(100)

false

100 is Prime