Semiprime Calculator

The Semiprime Calculator is a free online tool used to check whether the number is semiprime.

A semiprime is a positive integer that can be represented by the product of two prime numbers. The two prime numbers can be the same or different.

For example, 21 = 3 * 7, where 3 and 7 are both prime numbers, so 21 is a semiprime. Another example, 9 = 3 * 3, so 9 is also a semiprime.

First 100 semiprimes

• 4 = 2 * 2
• 6 = 2 * 3
• 9 = 3 * 3
• 10 = 2 * 5
• 14 = 2 * 7
• 15 = 3 * 5
• 21 = 3 * 7
• 22 = 2 * 11
• 25 = 5 * 5
• 26 = 2 * 13
• 33 = 3 * 11
• 34 = 2 * 17
• 35 = 5 * 7
• 38 = 2 * 19
• 39 = 3 * 13
• 46 = 2 * 23
• 49 = 7 * 7
• 51 = 3 * 17
• 55 = 5 * 11
• 57 = 3 * 19
• 58 = 2 * 29
• 62 = 2 * 31
• 65 = 5 * 13
• 69 = 3 * 23
• 74 = 2 * 37
• 77 = 7 * 11
• 82 = 2 * 41
• 85 = 5 * 17
• 86 = 2 * 43
• 87 = 3 * 29
• 91 = 7 * 13
• 93 = 3 * 31
• 94 = 2 * 47
• 95 = 5 * 19
• 106 = 2 * 53
• 111 = 3 * 37
• 115 = 5 * 23
• 118 = 2 * 59
• 119 = 7 * 17
• 121 = 11 * 11
• 122 = 2 * 61
• 123 = 3 * 41
• 129 = 3 * 43
• 133 = 7 * 19
• 134 = 2 * 67
• 141 = 3 * 47
• 142 = 2 * 71
• 143 = 11 * 13
• 145 = 5 * 29
• 146 = 2 * 73
• 155 = 5 * 31
• 158 = 2 * 79
• 159 = 3 * 53
• 161 = 7 * 23
• 166 = 2 * 83
• 169 = 13 * 13
• 177 = 3 * 59
• 178 = 2 * 89
• 183 = 3 * 61
• 185 = 5 * 37
• 187 = 11 * 17
• 194 = 2 * 97
• 201 = 3 * 67
• 202 = 2 * 101
• 203 = 7 * 29
• 205 = 5 * 41
• 206 = 2 * 103
• 209 = 11 * 19
• 213 = 3 * 71
• 214 = 2 * 107
• 215 = 5 * 43
• 217 = 7 * 31
• 218 = 2 * 109
• 219 = 3 * 73
• 221 = 13 * 17
• 226 = 2 * 113
• 235 = 5 * 47
• 237 = 3 * 79
• 247 = 13 * 19
• 249 = 3 * 83
• 253 = 11 * 23
• 254 = 2 * 127
• 259 = 7 * 37
• 262 = 2 * 131
• 265 = 5 * 53
• 267 = 3 * 89
• 274 = 2 * 137
• 278 = 2 * 139
• 287 = 7 * 41
• 289 = 17 * 17
• 291 = 3 * 97
• 295 = 5 * 59
• 298 = 2 * 149
• 299 = 13 * 23
• 301 = 7 * 43
• 302 = 2 * 151
• 303 = 3 * 101
• 305 = 5 * 61
• 309 = 3 * 103
• 314 = 2 * 157

The procedure to use the semiprime calculator is as follows: