# 31

## 31 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 31 look like?

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

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

## Prime factorization of 31:

### 31

See below for interesting mathematical facts about the number 31 from the Numbermatics database.

### Names of 31

• Cardinal: 31 can be written as Thirty-one.

### Scientific notation

• Scientific notation: 3.1 × 101

### Factors of 31

• Number of distinct prime factors ω(n): 1
• Total number of prime factors Ω(n): 1
• Sum of prime factors: 31

### Divisors of 31

• Number of divisors d(n): 2
• Complete list of divisors:
• Sum of all divisors σ(n): 32
• Sum of proper divisors (its aliquot sum) s(n): 1
• 31 is a deficient number, because the sum of its proper divisors (1) is less than itself. Its deficiency is 30

### Bases of 31

• Binary: 111112
• Base-36: V

### Squares and roots of 31

• 31 squared (312) is 961
• 31 cubed (313) is 29791
• The square root of 31 is 5.5677643629
• The cube root of 31 is 3.1413806523

### Scales and comparisons

How big is 31?
• A cube with a volume of 31 cubic inches would be around 0.3 feet tall.

### Recreational maths with 31

• 31 backwards is 13
• The number of decimal digits it has is: 2
• The sum of 31's digits is 4
• More coming soon!