# 990

## 990 is an even composite number composed of four prime numbers multiplied together.

What does the number 990 look like?

This visualization shows the relationship between its 4 prime factors (large circles) and 24 divisors.

990 is an even composite number. It is composed of four distinct prime numbers multiplied together. It has a total of twenty-four divisors.

## Prime factorization of 990:

### 2 × 32 × 5 × 11

(2 × 3 × 3 × 5 × 11)

See below for interesting mathematical facts about the number 990 from the Numbermatics database.

### Names of 990

• Cardinal: 990 can be written as Nine hundred ninety.

### Scientific notation

• Scientific notation: 9.9 × 102

### Factors of 990

• Number of distinct prime factors ω(n): 4
• Total number of prime factors Ω(n): 5
• Sum of prime factors: 21

### Divisors of 990

• Number of divisors d(n): 24
• Complete list of divisors:
• Sum of all divisors σ(n): 2808
• Sum of proper divisors (its aliquot sum) s(n): 1818
• 990 is an abundant number, because the sum of its proper divisors (1818) is greater than itself. Its abundance is 828

### Bases of 990

• Binary: 11110111102
• Base-36: RI

### Squares and roots of 990

• 990 squared (9902) is 980100
• 990 cubed (9903) is 970299000
• The square root of 990 is 31.4642654451
• The cube root of 990 is 9.9665549341

### Scales and comparisons

How big is 990?
• 990 seconds is equal to 16 minutes, 30 seconds.
• To count from 1 to 990 would take you about eight 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 990 cubic inches would be around 0.8 feet tall.

### Recreational maths with 990

• 990 backwards is 099
• 990 is a Harshad number.
• The number of decimal digits it has is: 3
• The sum of 990's digits is 18
• More coming soon!