Q: Is 21,645,351 a Composite Number?

Why is 21,645,351 a composite number?

A composite number is a number that can be divided evenly by more numbers than 1 and itself. It is the opposite of a prime number.

The number 21,645,351 can be evenly divided by 1 3 7 9 13 19 21 39 57 63 91 107 117 133 169 171 247 273 321 399 507 741 749 819 963 1,183 1,197 1,391 1,521 1,729 2,033 2,223 2,247 3,211 3,549 4,173 5,187 6,099 6,741 9,633 9,737 10,647 12,519 14,231 15,561 18,083 18,297 22,477 26,429 28,899 29,211 42,693 54,249 67,431 79,287 87,633 126,581 128,079 162,747 185,003 202,293 237,861 343,577 379,743 555,009 1,030,731 1,139,229 1,665,027 2,405,039 3,092,193 7,215,117 and 21,645,351, with no remainder.

Since 21,645,351 cannot be divided by just 1 and 21,645,351, it is a composite number.

More Examples

• All positive natural numbers are either a prime number or a composite number (except the number 1, which is neither).