##### Wiktionary

**semiprime**

n. (context mathematics English) A natural number that is the product of two prime numbers.

##### Wikipedia

**Semiprime**

In mathematics, a **semiprime** (also called **biprime** or **2- almost prime**, or **pq number**) is a natural number that is the product of two (not necessarily distinct) prime numbers. The semiprimes less than 100 are 4, 6, 9, 10, 14, 15, 21, 22, 25, 26, 33, 34, 35, 38, 39, 46, 49, 51, 55, 57, 58, 62, 65, 69, 74, 77, 82, 85, 86, 87, 91, 93, 94, and 95. . Semiprimes that are not perfect squares are called discrete, or distinct, semiprimes.

By definition, semiprime numbers have no composite factors other than themselves. For example, the number 26 is semiprime and its only factors are 1, 2, 13, and 26.