# 128

## 128 is an even composite number. It is composed of a single prime number multiplied by itself six times.

What does the number 128 look like?

This visualization shows the relationship between its 1 prime factors (large circles) and 8 divisors.

128 is an even composite number. It is composed of one distinct prime number multiplied by itself six times. It has a total of eight divisors.

## Prime factorization of 128:

### 27

(2 × 2 × 2 × 2 × 2 × 2 × 2)

See below for interesting mathematical facts about the number 128 from the Numbermatics database.

### Names of 128

• Cardinal: 128 can be written as One hundred twenty-eight.

### Scientific notation

• Scientific notation: 1.28 × 102

### Factors of 128

• Number of distinct prime factors ω(n): 1
• Total number of prime factors Ω(n): 7
• Sum of prime factors: 2

### Divisors of 128

• Number of divisors d(n): 8
• Complete list of divisors:
• Sum of all divisors σ(n): 255
• Sum of proper divisors (its aliquot sum) s(n): 127
• 128 is a deficient number, because the sum of its proper divisors (127) is less than itself. Its deficiency is 1

### Bases of 128

• Binary: 100000002
• Base-36: 3K

### Squares and roots of 128

• 128 squared (1282) is 16384
• 128 cubed (1283) is 2097152
• The square root of 128 is 11.3137084991
• The cube root of 128 is 5.0396841995

### Scales and comparisons

How big is 128?
• 128 seconds is equal to 2 minutes, 8 seconds.
• To count from 1 to 128 would take you about four seconds.

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 128 cubic inches would be around 0.4 feet tall.

### Recreational maths with 128

• 128 backwards is 821
• The number of decimal digits it has is: 3
• The sum of 128's digits is 11
• More coming soon!