# 2561

## 2,561 is an odd composite number composed of two prime numbers multiplied together.

What does the number 2561 look like?

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

2561 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 2561:

### 13 × 197

See below for interesting mathematical facts about the number 2561 from the Numbermatics database.

### Names of 2561

• Cardinal: 2561 can be written as Two thousand, five hundred sixty-one.

### Scientific notation

• Scientific notation: 2.561 × 103

### Factors of 2561

• Number of distinct prime factors ω(n): 2
• Total number of prime factors Ω(n): 2
• Sum of prime factors: 210

### Divisors of 2561

• Number of divisors d(n): 4
• Complete list of divisors:
• Sum of all divisors σ(n): 2772
• Sum of proper divisors (its aliquot sum) s(n): 211
• 2561 is a deficient number, because the sum of its proper divisors (211) is less than itself. Its deficiency is 2350

### Bases of 2561

• Binary: 1010000000012
• Base-36: 1Z5

### Squares and roots of 2561

• 2561 squared (25612) is 6558721
• 2561 cubed (25613) is 16796884481
• The square root of 2561 is 50.6063237155
• The cube root of 2561 is 13.6815885665

### Scales and comparisons

How big is 2561?
• 2,561 seconds is equal to 42 minutes, 41 seconds.
• To count from 1 to 2,561 would take you about forty-two 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 2561 cubic inches would be around 1.1 feet tall.

### Recreational maths with 2561

• 2561 backwards is 1652
• The number of decimal digits it has is: 4
• The sum of 2561's digits is 14
• More coming soon!