# 686

## 686 is an even composite number composed of two prime numbers multiplied together.

What does the number 686 look like?

This visualization shows the relationship between its 2 prime factors (large circles) and 8 divisors.

686 is an even composite number. It is composed of two distinct prime numbers multiplied together. It has a total of eight divisors.

## Prime factorization of 686:

### 2 × 73

(2 × 7 × 7 × 7)

See below for interesting mathematical facts about the number 686 from the Numbermatics database.

### Names of 686

• Cardinal: 686 can be written as Six hundred eighty-six.

### Scientific notation

• Scientific notation: 6.86 × 102

### Factors of 686

• Number of distinct prime factors ω(n): 2
• Total number of prime factors Ω(n): 4
• Sum of prime factors: 9

### Divisors of 686

• Number of divisors d(n): 8
• Complete list of divisors:
• Sum of all divisors σ(n): 1200
• Sum of proper divisors (its aliquot sum) s(n): 514
• 686 is a deficient number, because the sum of its proper divisors (514) is less than itself. Its deficiency is 172

### Bases of 686

• Binary: 10101011102
• Base-36: J2

### Squares and roots of 686

• 686 squared (6862) is 470596
• 686 cubed (6863) is 322828856
• The square root of 686 is 26.1916017075
• The cube root of 686 is 8.8194473493

### Scales and comparisons

How big is 686?
• 686 seconds is equal to 11 minutes, 26 seconds.
• To count from 1 to 686 would take you about five 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 686 cubic inches would be around 0.7 feet tall.

### Recreational maths with 686

• 686 is the same when its digits are reversed! That makes it a palindromic number.
• The number of decimal digits it has is: 3
• The sum of 686's digits is 20
• More coming soon!