A number made by multiplying exactly two prime numbers.
Example: 3 × 7 = 21
3 and 7 are prime numbers, so 21 is semiprime
Example: 2 × 2 = 4
2 is prime, so 4 is semiprime (it is OK to multiply the same prime number)
A number made by multiplying exactly two prime numbers.
Example: 3 × 7 = 21
3 and 7 are prime numbers, so 21 is semiprime
Example: 2 × 2 = 4
2 is prime, so 4 is semiprime (it is OK to multiply the same prime number)