# 21456

## 21,456 is an even composite number composed of three prime numbers multiplied together.

What does the number 21456 look like?

This visualization shows the relationship between its 3 prime factors (large circles) and 30 divisors.

21456 is an even composite number. It is composed of three distinct prime numbers multiplied together. It has a total of thirty divisors.

## Prime factorization of 21456:

### 24 × 32 × 149

(2 × 2 × 2 × 2 × 3 × 3 × 149)

See below for interesting mathematical facts about the number 21456 from the Numbermatics database.

### Names of 21456

• Cardinal: 21456 can be written as Twenty-one thousand, four hundred fifty-six.

### Scientific notation

• Scientific notation: 2.1456 × 104

### Factors of 21456

• Number of distinct prime factors ω(n): 3
• Total number of prime factors Ω(n): 7
• Sum of prime factors: 154

### Divisors of 21456

• Number of divisors d(n): 30
• Complete list of divisors:
• Sum of all divisors σ(n): 60450
• Sum of proper divisors (its aliquot sum) s(n): 38994
• 21456 is an abundant number, because the sum of its proper divisors (38994) is greater than itself. Its abundance is 17538

### Bases of 21456

• Binary: 1010011110100002
• Base-36: GK0

### Squares and roots of 21456

• 21456 squared (214562) is 460359936
• 21456 cubed (214563) is 9877482786816
• The square root of 21456 is 146.4786673889
• The cube root of 21456 is 27.7875071103

### Scales and comparisons

How big is 21456?
• 21,456 seconds is equal to 5 hours, 57 minutes, 36 seconds.
• To count from 1 to 21,456 would take you about five hours.

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 21456 cubic inches would be around 2.3 feet tall.

### Recreational maths with 21456

• 21456 backwards is 65412
• 21456 is a Harshad number.
• The number of decimal digits it has is: 5
• The sum of 21456's digits is 18
• More coming soon!