# 221

## 221 is an odd composite number composed of two prime numbers multiplied together.

What does the number 221 look like?

This visualization shows the relationship between its 2 prime factors (large circles) and 4 divisors.

221 is an odd composite number. It is composed of two distinct prime numbers multiplied together. It has a total of four divisors.

## Prime factorization of 221:

### 13 × 17

See below for interesting mathematical facts about the number 221 from the Numbermatics database.

### Names of 221

• Cardinal: 221 can be written as Two hundred twenty-one.

### Scientific notation

• Scientific notation: 2.21 × 102

### Factors of 221

• Number of distinct prime factors ω(n): 2
• Total number of prime factors Ω(n): 2
• Sum of prime factors: 30

### Divisors of 221

• Number of divisors d(n): 4
• Complete list of divisors:
• Sum of all divisors σ(n): 252
• Sum of proper divisors (its aliquot sum) s(n): 31
• 221 is a deficient number, because the sum of its proper divisors (31) is less than itself. Its deficiency is 190

### Bases of 221

• Binary: 110111012
• Base-36: 65

### Squares and roots of 221

• 221 squared (2212) is 48841
• 221 cubed (2213) is 10793861
• The square root of 221 is 14.8660687473
• The cube root of 221 is 6.0459435961

### Scales and comparisons

How big is 221?
• 221 seconds is equal to 3 minutes, 41 seconds.
• To count from 1 to 221 would take you about fifty seconds.

This is a very rough estimate, based on a speaking rate of half a second every third order of magnitude. If you speak quickly, you could probably say any randomly-chosen number between one and a thousand in around half a second. Very big numbers obviously take longer to say, so we add half a second for every extra x1000. (We do not count involuntary pauses, bathroom breaks or the necessity of sleep in our calculation!)

• A cube with a volume of 221 cubic inches would be around 0.5 feet tall.

### Recreational maths with 221

• 221 backwards is 122
• The number of decimal digits it has is: 3
• The sum of 221's digits is 5
• More coming soon!