# Compare 13 vs 28

Property | 13 | 28 |
---|---|---|

Type | prime | composite number |

Unique factors | 1 | 2 |

Total factors | 1 | 3 |

Prime factorization | 13^{1} | 2^{2} × 7^{1} |

Prime factorization | 13 | 2 × 2 × 7 |

Divisors count | 2 | 6 |

Divisors | 1, 13 | 1, 2, 4, 7, 14, 28 |

Number of properties | 32 | 0 |

Centered square primes | 2nd | |

Chen primes | 6th | |

Cousin primes (1st member) | 3rd | |

Cuban primes 2 | 1st | |

Emirps | 1st | |

Fibonacci primes | 4th | |

Happy primes | 2nd | |

Harmonic primes | 2nd | |

Left-truncatable primes | 5th | |

Lucky primes | 3rd | |

Multiplicative primes | 5th | |

Pierpont primes | 5th | |

Primes | 6th | |

Prime quadruplets (2nd member) | 2nd | |

Prime quadruplets (4th member) | 1st | |

Prime quintuplet 1s (3rd member) | 1st | |

Prime quintuplet 2s (2nd member) | 2nd | |

Prime quintuplet 2s (4th member) | 1st | |

Prime sextuplets (3rd member) | 1st | |

Prime triplets (1st member) | 4th | |

Prime triplets (2nd member) | 3rd | |

Prime triplets (3rd member) | 2nd | |

Proth primes | 3rd | |

Pythagorean primes | 2nd | |

Sexy primes (1st member) | 4th | |

Sexy primes (2nd member) | 2nd | |

Sexy prime triplets (2nd member) | 2nd | |

Solinas primes | 5th | |

Thabit primes of the 2nd kind | 2nd | |

Twin primes (2nd member) | 3rd | |

Ulam primes | 4th | |

Wilson primes | 2nd | |

Roman numberals | XIII | XXVIII |

Base 2 | 1101_{2} | 11100_{2} |

Base 3 | 111_{3} | 1001_{3} |

Base 4 | 31_{4} | 130_{4} |

Base 5 | 23_{5} | 103_{5} |

Base 6 | 21_{6} | 44_{6} |

Base 7 | 16_{7} | 40_{7} |

Base 8 | 15_{8} | 34_{8} |

Base 9 | 14_{9} | 31_{9} |

Base 10 | 13_{10} | 28_{10} |

Base 11 | 12_{11} | 26_{11} |

Base 12 | 11_{12} | 24_{12} |

Base 13 | 10_{13} | 22_{13} |

Base 14 | d_{14} | 20_{14} |

Base 15 | d_{15} | 1d_{15} |

Base 16 | d_{16} | 1c_{16} |