Number 7 - properties and curiosities

7 (number)

7

Number 7 properties

  • Prime
  • Happy
  • Palindrome
  • Harshad
  • Armstrong
  • Mersenne
  • 7 is an odd number.
  • 7 is a palindrome.
  • 7 is a prime number, which means it is only divisible by 1 and itself.
  • 7 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.
  • 7 is a Harshad number, which means it is divisible by the sum of its digits (7 = 7, and 7 is divisible by 7).

Prime factorization

Prime factorization of 7: 7.

Divisors

Divisor count: 2

1, 7

Factors of 7 are: 1, 7.

Representations

In octal, 7 is represented as 7.

In binary, 7 is represented as 111.

In hex, 7 is represented as 7.

Roman numeral: VII

Curiosities

  • 7 is part of the infinite sequence of prime numbers.
  • 7 reads the same from left to right and right to left.
  • 7 is divisible by the sum of its digits.

Quick answers

Is 7 prime?
Yes, 7 is prime.

What are the factors of 7?
1, 7

What is 7 in binary?
111