# 1391

## 1,391 is an odd composite number composed of two prime numbers multiplied together.

What does the number 1391 look like?

This visualization shows the relationship between its 2 prime factors (large circles) and 4 divisors.

1391 is an odd composite number. It is composed of two distinct prime numbers multiplied together. It has a total of four divisors.

## Prime factorization of 1391:

### 13 × 107

See below for interesting mathematical facts about the number 1391 from the Numbermatics database.

### Names of 1391

• Cardinal: 1391 can be written as One thousand, three hundred ninety-one.

### Scientific notation

• Scientific notation: 1.391 × 103

### Factors of 1391

• Number of distinct prime factors ω(n): 2
• Total number of prime factors Ω(n): 2
• Sum of prime factors: 120

### Divisors of 1391

• Number of divisors d(n): 4
• Complete list of divisors:
• Sum of all divisors σ(n): 1512
• Sum of proper divisors (its aliquot sum) s(n): 121
• 1391 is a deficient number, because the sum of its proper divisors (121) is less than itself. Its deficiency is 1270

### Bases of 1391

• Binary: 101011011112
• Base-36: 12N

### Squares and roots of 1391

• 1391 squared (13912) is 1934881
• 1391 cubed (13913) is 2691419471
• The square root of 1391 is 37.2961123981
• The cube root of 1391 is 11.1628659623

### Scales and comparisons

How big is 1391?
• 1,391 seconds is equal to 23 minutes, 11 seconds.
• To count from 1 to 1,391 would take you about twenty-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 1391 cubic inches would be around 0.9 feet tall.

### Recreational maths with 1391

• 1391 backwards is 1931
• The number of decimal digits it has is: 4
• The sum of 1391's digits is 14
• More coming soon!