# 644

## 644 is an even composite number composed of three prime numbers multiplied together.

What does the number 644 look like?

This visualization shows the relationship between its 3 prime factors (large circles) and 12 divisors.

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

## Prime factorization of 644:

### 22 × 7 × 23

(2 × 2 × 7 × 23)

See below for interesting mathematical facts about the number 644 from the Numbermatics database.

### Names of 644

• Cardinal: 644 can be written as Six hundred forty-four.

### Scientific notation

• Scientific notation: 6.44 × 102

### Factors of 644

• Number of distinct prime factors ω(n): 3
• Total number of prime factors Ω(n): 4
• Sum of prime factors: 32

### Divisors of 644

• Number of divisors d(n): 12
• Complete list of divisors:
• Sum of all divisors σ(n): 1344
• Sum of proper divisors (its aliquot sum) s(n): 700
• 644 is an abundant number, because the sum of its proper divisors (700) is greater than itself. Its abundance is 56

### Bases of 644

• Binary: 10100001002
• Base-36: HW

### Squares and roots of 644

• 644 squared (6442) is 414736
• 644 cubed (6443) is 267089984
• The square root of 644 is 25.3771550809
• The cube root of 644 is 8.6356551085

### Scales and comparisons

How big is 644?
• 644 seconds is equal to 10 minutes, 44 seconds.
• To count from 1 to 644 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 644 cubic inches would be around 0.7 feet tall.

### Recreational maths with 644

• 644 backwards is 446
• 644 is a Harshad number.
• The number of decimal digits it has is: 3
• The sum of 644's digits is 14
• More coming soon!