# 638

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

What does the number 638 look like?

This visualization shows the relationship between its 3 prime factors (large circles) and 8 divisors.

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

## Prime factorization of 638:

### 2 × 11 × 29

See below for interesting mathematical facts about the number 638 from the Numbermatics database.

### Names of 638

• Cardinal: 638 can be written as Six hundred thirty-eight.

### Scientific notation

• Scientific notation: 6.38 × 102

### Factors of 638

• Number of distinct prime factors ω(n): 3
• Total number of prime factors Ω(n): 3
• Sum of prime factors: 42

### Divisors of 638

• Number of divisors d(n): 8
• Complete list of divisors:
• Sum of all divisors σ(n): 1080
• Sum of proper divisors (its aliquot sum) s(n): 442
• 638 is a deficient number, because the sum of its proper divisors (442) is less than itself. Its deficiency is 196

### Bases of 638

• Binary: 10011111102
• Base-36: HQ

### Squares and roots of 638

• 638 squared (6382) is 407044
• 638 cubed (6383) is 259694072
• The square root of 638 is 25.2586618805
• The cube root of 638 is 8.6087525819

### Scales and comparisons

How big is 638?
• 638 seconds is equal to 10 minutes, 38 seconds.
• To count from 1 to 638 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 638 cubic inches would be around 0.7 feet tall.

### Recreational maths with 638

• 638 backwards is 836
• The number of decimal digits it has is: 3
• The sum of 638's digits is 17
• More coming soon!