# 891

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

What does the number 891 look like?

This visualization shows the relationship between its 2 prime factors (large circles) and 10 divisors.

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

## Prime factorization of 891:

### 34 × 11

(3 × 3 × 3 × 3 × 11)

See below for interesting mathematical facts about the number 891 from the Numbermatics database.

### Names of 891

• Cardinal: 891 can be written as Eight hundred ninety-one.

### Scientific notation

• Scientific notation: 8.91 × 102

### Factors of 891

• Number of distinct prime factors ω(n): 2
• Total number of prime factors Ω(n): 5
• Sum of prime factors: 14

### Divisors of 891

• Number of divisors d(n): 10
• Complete list of divisors:
• Sum of all divisors σ(n): 1452
• Sum of proper divisors (its aliquot sum) s(n): 561
• 891 is a deficient number, because the sum of its proper divisors (561) is less than itself. Its deficiency is 330

### Bases of 891

• Binary: 11011110112
• Base-36: OR

### Squares and roots of 891

• 891 squared (8912) is 793881
• 891 cubed (8913) is 707347971
• The square root of 891 is 29.8496231132
• The cube root of 891 is 9.6226029899

### Scales and comparisons

How big is 891?
• 891 seconds is equal to 14 minutes, 51 seconds.
• To count from 1 to 891 would take you about seven 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 891 cubic inches would be around 0.8 feet tall.

### Recreational maths with 891

• 891 backwards is 198
• The number of decimal digits it has is: 3
• The sum of 891's digits is 18
• More coming soon!