# 661

## 661 is a prime number. Like all primes greater than two, it is odd and has no factors apart from itself and one.

What does the number 661 look like?

As a prime, it is not composed of any other numbers and has no internal structure.

661 is a prime number. Like all primes (except two), it is an odd number.

## Prime factorization of 661:

### 661

See below for interesting mathematical facts about the number 661 from the Numbermatics database.

### Names of 661

• Cardinal: 661 can be written as Six hundred sixty-one.

### Scientific notation

• Scientific notation: 6.61 × 102

### Factors of 661

• Number of distinct prime factors ω(n): 1
• Total number of prime factors Ω(n): 1
• Sum of prime factors: 661

### Divisors of 661

• Number of divisors d(n): 2
• Complete list of divisors:
• Sum of all divisors σ(n): 662
• Sum of proper divisors (its aliquot sum) s(n): 1
• 661 is a deficient number, because the sum of its proper divisors (1) is less than itself. Its deficiency is 660

### Bases of 661

• Binary: 10100101012
• Base-36: ID

### Squares and roots of 661

• 661 squared (6612) is 436921
• 661 cubed (6613) is 288804781
• The square root of 661 is 25.7099202643
• The cube root of 661 is 8.7109827387

### Scales and comparisons

How big is 661?
• 661 seconds is equal to 11 minutes, 1 second.
• To count from 1 to 661 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 661 cubic inches would be around 0.7 feet tall.

### Recreational maths with 661

• 661 backwards is 166
• The number of decimal digits it has is: 3
• The sum of 661's digits is 13
• More coming soon!

MLA style:
"Number 661 - Facts about the integer". Numbermatics.com. 2021. Web. 23 October 2021.

APA style:
Numbermatics. (2021). Number 661 - Facts about the integer. Retrieved 23 October 2021, from https://numbermatics.com/n/661/

Chicago style:
Numbermatics. 2021. "Number 661 - Facts about the integer". https://numbermatics.com/n/661/

The information we have on file for 661 includes mathematical data and numerical statistics calculated using standard algorithms and methods. We are adding more all the time. If there are any features you would like to see, please contact us. Information provided for educational use, intellectual curiosity and fun!

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