# 21986721

## 21,986,721 is an odd composite number composed of two prime numbers multiplied together.

What does the number 21986721 look like?

This visualization shows the relationship between its 2 prime factors (large circles) and 15 divisors.

21986721 is an odd composite number. It is composed of two distinct prime numbers multiplied together. It has a total of fifteen divisors.

## Prime factorization of 21986721:

### 34 × 5212

(3 × 3 × 3 × 3 × 521 × 521)

See below for interesting mathematical facts about the number 21986721 from the Numbermatics database.

### Names of 21986721

• Cardinal: 21986721 can be written as Twenty-one million, nine hundred eighty-six thousand, seven hundred twenty-one.

### Scientific notation

• Scientific notation: 2.1986721 × 107

### Factors of 21986721

• Number of distinct prime factors ω(n): 2
• Total number of prime factors Ω(n): 6
• Sum of prime factors: 524

### Divisors of 21986721

• Number of divisors d(n): 15
• Complete list of divisors:
• Sum of all divisors σ(n): 32907523
• Sum of proper divisors (its aliquot sum) s(n): 10920802
• 21986721 is a deficient number, because the sum of its proper divisors (10920802) is less than itself. Its deficiency is 11065919

### Bases of 21986721

• Binary: 10100111101111101101000012
• Base-36: D3929

### Scales and comparisons

How big is 21986721?
• 21,986,721 seconds is equal to 36 weeks, 2 days, 11 hours, 25 minutes, 21 seconds.
• To count from 1 to 21,986,721 would take you about two weeks!

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 21986721 cubic inches would be around 23.3 feet tall.

### Recreational maths with 21986721

• 21986721 backwards is 12768912
• The number of decimal digits it has is: 8
• The sum of 21986721's digits is 36
• More coming soon!