# 561

## 561 is an odd composite number composed of three prime numbers multiplied together.

What does the number 561 look like?

This visualization shows the relationship between its 3 prime factors (large circles) and 8 divisors.

561 is an odd composite number. It is composed of three distinct prime numbers multiplied together. It has a total of eight divisors.

## Prime factorization of 561:

### 3 × 11 × 17

See below for interesting mathematical facts about the number 561 from the Numbermatics database.

### Names of 561

• Cardinal: 561 can be written as Five hundred sixty-one.

### Scientific notation

• Scientific notation: 5.61 × 102

### Factors of 561

• Number of distinct prime factors ω(n): 3
• Total number of prime factors Ω(n): 3
• Sum of prime factors: 31

### Divisors of 561

• Number of divisors d(n): 8
• Complete list of divisors:
• Sum of all divisors σ(n): 864
• Sum of proper divisors (its aliquot sum) s(n): 303
• 561 is a deficient number, because the sum of its proper divisors (303) is less than itself. Its deficiency is 258

### Bases of 561

• Binary: 10001100012
• Base-36: FL

### Squares and roots of 561

• 561 squared (5612) is 314721
• 561 cubed (5613) is 176558481
• The square root of 561 is 23.6854385647
• The cube root of 561 is 8.2474739741

### Scales and comparisons

How big is 561?
• 561 seconds is equal to 9 minutes, 21 seconds.
• To count from 1 to 561 would take you about four minutes.

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 561 cubic inches would be around 0.7 feet tall.

### Recreational maths with 561

• 561 backwards is 165
• The number of decimal digits it has is: 3
• The sum of 561's digits is 12
• More coming soon!