title: 313 (number)
text: # 313 (number)
  
  313 (three hundred [and] thirteen) is the natural number following 312 and preceding 314.
  
  Additionally, 313 is:
  
  * a prime number
  * a twin prime with 311
  * a centered square number
  * a full reptend prime (and the smallest number which is a full reptend prime in base 10 but not in base 2 to 9)
  * a Pythagorean prime
  * a regular prime
  * a palindromic prime in both decimal and binary.
  * a truncatable prime
  * a weakly prime in base 5
  * a happy number
  * an Armstrong number - in base 4 ( $3×4^2$ + $1×4^1$ + $3×4^0$ = $3^3$ + $1^3$ + $3^3$ )
  * an index of a prime Lucas number.
  