13 x 17
13 x 17 = 221
13 times 17 = 221
Apart from itself and 1, the only numbers that divide evenly into 221 are 13 and 17. Therefore, 221 = 13 x 17.
8x19
There are no two primes whose sum is 221.
Apart from itself and 1, the only numbers that divide evenly into 221 are 13 and 17. Therefore, 221 = 13 x 17.
17 & 13
1, 13, 17, 221.
221, 442, 663, 884 and so on.
1, 13, 17 and 221.
221
Francium 221
63 and 49
208 and 221, among others.
You have four digits, each of which could be any of ten possible numbers, so the total number of possibilities is 10 x 10 x 10 x 10 = 10,000. However, since De Witt actually has two prefixes, (563) 659 and 221, it could have as many as 20,000 phone numbers. Of course, 221 numbers can only start with 221-1, 221-8, or 221-9, so it's really only 13,000 possible numbers.
The prime factors of 221 are 13 and 17. They're the only prime numbers that will divide evenly into 221 with no remainder.