Encyclopedia > Composite number

Article Content

Composite number

A composite number is a natural number larger than 1 that is not a prime number. The first ten composite numbers are:

4, 6, 8, 9, 10, 12, 14, 15, 16 and 18.

A composite number which has precisely three distinct prime factors is called a sphenic number.

The ten first sphenic numbers are:

30; which is also 11-agonal by polygonality and bracketed by twin primes
42; which is bracketed by twin primes
66; which is also triangular, hexagonal, 23-agonal and a palindrome
70; which is also pentagonal and 13-agonal
78
102; which is bracketed by twin primes
105; which is also 12-agonal
110
114
130; which is also 23-agonal

All Wikipedia text is available under the terms of the GNU Free Documentation License

Search Encyclopedia

Search over one million articles, find something about almost anything!

Featured Article

Wheatley Heights, New York

... age 18 and over, there are 89.3 males. The median income for a household in the town is $75,076, and the median income for a family is $79,745. Males have a median income ...