Number Gossip

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Unique Properties of 1105

  • 1105 is the smallest Carmichael number whose reversal is prime
  • 1105 is the smallest pseudoprime to both base 2 and base 3. BTW, it is also a pseudoprime to base 7
  • 1105 is the largest 4-digit pseudoprime to base 2
  • 1105 is the smallest hypotenuse of exactly 13 distinct Pythagorean triangles
  • 1105 is the smallest number such that n, n+1 and their sum have at least 3 distinct prime factors
  • 1105 is the smallest hypotenuse of a right triangle which is the product of three distinct odd primes
  • 1105 is the smallest Carmichael number that is the sum of two squares
  • 1105 is the smallest Fermat pseudoprime to base 2 that is decagonal

Rare Properties of 1105

Carmichael

Common Properties of 1105

Apocalyptic power
Composite
Deficient
Evil
Lucky
Odd
Square-free