# 729

## 729 is an odd composite number. It is composed of a single prime number multiplied by itself five times.

What does the number 729 look like?

This visualization shows the relationship between its 1 prime factors (large circles) and 7 divisors.

729 is an odd composite number. It is composed of one distinct prime number multiplied by itself five times. It has a total of seven divisors.

## Prime factorization of 729:

### 36

(3 × 3 × 3 × 3 × 3 × 3)

See below for interesting mathematical facts about the number 729 from the Numbermatics database.

### Names of 729

• Cardinal: 729 can be written as Seven hundred twenty-nine.

### Scientific notation

• Scientific notation: 7.29 × 102

### Factors of 729

• Number of distinct prime factors ω(n): 1
• Total number of prime factors Ω(n): 6
• Sum of prime factors: 3

### Divisors of 729

• Number of divisors d(n): 7
• Complete list of divisors:
• Sum of all divisors σ(n): 1093
• Sum of proper divisors (its aliquot sum) s(n): 364
• 729 is a deficient number, because the sum of its proper divisors (364) is less than itself. Its deficiency is 365

### Bases of 729

• Binary: 10110110012
• Base-36: K9

### Squares and roots of 729

• 729 squared (7292) is 531441
• 729 cubed (7293) is 387420489
• 729 is a perfect square number. Its square root is 27
• 729 is a perfect cube number. Its cube root is 9
• Being both a perfect square and a perfect cube, 729 is also a perfect sixth number.

### Scales and comparisons

How big is 729?
• 729 seconds is equal to 12 minutes, 9 seconds.
• To count from 1 to 729 would take you about six 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 729 cubic inches would be around 0.8 feet tall.

### Recreational maths with 729

• 729 backwards is 927
• The number of decimal digits it has is: 3
• The sum of 729's digits is 18
• More coming soon!