# 399

## 399 is an odd composite number composed of three prime numbers multiplied together.

What does the number 399 look like?

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

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

## Prime factorization of 399:

### 3 × 7 × 19

See below for interesting mathematical facts about the number 399 from the Numbermatics database.

### Names of 399

• Cardinal: 399 can be written as Three hundred ninety-nine.

### Scientific notation

• Scientific notation: 3.99 × 102

### Factors of 399

• Number of distinct prime factors ω(n): 3
• Total number of prime factors Ω(n): 3
• Sum of prime factors: 29

### Divisors of 399

• Number of divisors d(n): 8
• Complete list of divisors:
• Sum of all divisors σ(n): 640
• Sum of proper divisors (its aliquot sum) s(n): 241
• 399 is a deficient number, because the sum of its proper divisors (241) is less than itself. Its deficiency is 158

### Bases of 399

• Binary: 1100011112
• Base-36: B3

### Squares and roots of 399

• 399 squared (3992) is 159201
• 399 cubed (3993) is 63521199
• The square root of 399 is 19.9749843553
• The cube root of 399 is 7.3619178209

### Scales and comparisons

How big is 399?
• 399 seconds is equal to 6 minutes, 39 seconds.
• To count from 1 to 399 would take you about three 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 399 cubic inches would be around 0.6 feet tall.

### Recreational maths with 399

• 399 backwards is 993
• 399 is a Harshad number.
• The number of decimal digits it has is: 3
• The sum of 399's digits is 21
• More coming soon!