# 646

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

What does the number 646 look like?

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

646 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 646:

### 2 × 17 × 19

See below for interesting mathematical facts about the number 646 from the Numbermatics database.

### Names of 646

• Cardinal: 646 can be written as Six hundred forty-six.

### Scientific notation

• Scientific notation: 6.46 × 102

### Factors of 646

• Number of distinct prime factors ω(n): 3
• Total number of prime factors Ω(n): 3
• Sum of prime factors: 38

### Divisors of 646

• 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): 434
• 646 is a deficient number, because the sum of its proper divisors (434) is less than itself. Its deficiency is 212

### Bases of 646

• Binary: 10100001102
• Base-36: HY

### Squares and roots of 646

• 646 squared (6462) is 417316
• 646 cubed (6463) is 269586136
• The square root of 646 is 25.4165300543
• The cube root of 646 is 8.6445854719

### Scales and comparisons

How big is 646?
• 646 seconds is equal to 10 minutes, 46 seconds.
• To count from 1 to 646 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 646 cubic inches would be around 0.7 feet tall.

### Recreational maths with 646

• 646 is the same when its digits are reversed! That makes it a palindromic number.
• The number of decimal digits it has is: 3
• The sum of 646's digits is 16
• More coming soon!