4
Number 4 properties
- Perfect square
- Palindrome
- Harshad
- Armstrong
- 4 is an even number.
- 4 is a palindrome.
- 4 is a perfect square (2 × 2).
- 4 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.
- 4 is a Harshad number, which means it is divisible by the sum of its digits (4 = 4, and 4 is divisible by 4).
Prime factorization
Prime factorization of 4: 2^2.
Divisors
Divisor count: 3
1, 2, 4
Factors of 4 are: 1, 2, 4.
Representations
In octal, 4 is represented as 4.
In binary, 4 is represented as 100.
In hex, 4 is represented as 4.
Roman numeral: IV
Curiosities
- 4 is a perfect square, so it forms a square grid with equal side lengths.
- 4 reads the same from left to right and right to left.
- 4 is divisible by the sum of its digits.
Related numbers
Nearby primes: 2, 3, 5, 7, 11
Quick answers
Is 4 prime?
No, 4 is not prime.
What are the factors of 4?
1, 2, 4
What is 4 in binary?
100