NumberWonders.com

The fascinating world of numbers

Number 3 - properties and curiosities

3 (number)

3

Number 3 properties

  • Prime
  • Fibonacci
  • Palindrome
  • Harshad
  • Armstrong
  • Mersenne
  • Triangular
  • 3 is an odd number.
  • 3 is a palindrome.
  • 3 is a prime number, which means it is only divisible by 1 and itself.
  • 3 is a Sophie Germain prime, which means that 2 x 3 + 1 = 7 is also a prime number.
  • 3 is triangular and equals T2.
  • 3 is an Armstrong (or Narcissistic) number, which means it is the sum of its own digits each raised to the power of the number of digits.
  • 3 is Fibonacci number #4.
  • 3 is a Harshad number, which means it is divisible by the sum of its digits (3 = 3, and 3 is divisible by 3).

Digits: 1 | Sum of digits: 3 | Digital root: 3

How to Write 3 in Words

  • Cardinal (English words): three
  • Ordinal: 3rd (third)
  • Currency / Cheque format: three and 00/100 dollars

Prime factorization

Prime factorization of 3: 3.

Divisors

Divisor count: 2

1, 3

Factors of 3 are: 1, 3.

Factor Pairs of 3

Factor pairs are two integers that multiply together to equal 3:

  • 1 × 3 = 3

Divisibility Rules for 3

Quick divisibility check for 3 across common divisors:

Divisor Divisible? Calculation / Remainder
2 ✗ No (rem 1) 3 = 2 × 1 + 1
3 ✓ Yes 3 ÷ 3 = 1
4 ✗ No (rem 3) 3 = 4 × 0 + 3
5 ✗ No (rem 3) 3 = 5 × 0 + 3
6 ✗ No (rem 3) 3 = 6 × 0 + 3
8 ✗ No (rem 3) 3 = 8 × 0 + 3
9 ✗ No (rem 3) 3 = 9 × 0 + 3
10 ✗ No (rem 3) 3 = 10 × 0 + 3
11 ✗ No (rem 3) 3 = 11 × 0 + 3
12 ✗ No (rem 3) 3 = 12 × 0 + 3

Powers, Roots & Multiples of 3

3² = 9 | 3³ = 27 | √3 ≈ 1.7321 | ∛3 ≈ 1.4422

First 10 multiples of 3:

3×1=3, 3×2=6, 3×3=9, 3×4=12, 3×5=15, 3×6=18, 3×7=21, 3×8=24, 3×9=27, 3×10=30

Everyday Unit & Time Conversions for 3

  • 3 seconds = 0.05 minutes (0.00 hours)
  • 3 minutes = 0.05 hours (0.00 days)
  • 3 hours = 0.13 days (0.02 weeks)
  • 3 days ≈ 0.10 months (0.01 years)
  • 3 inches = 0.25 feet (7.62 cm)

Representations

In octal, 3 is represented as 3.

In binary, 3 is represented as 11.

In hex, 3 is represented as 3.

Roman numeral: III

Curiosities

  • 3 is part of the infinite sequence of prime numbers.
  • 3 appears in the Fibonacci sequence, where each number is the sum of the previous two.
  • 3 reads the same from left to right and right to left.

Quick answers

How do you write 3 in words?
three

Is 3 prime?
Yes, 3 is prime.

What are the factors of 3?
1, 3

What is 3 in binary?
11