Number Gossip

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Unique Properties of 39

  • 39 is the largest number that has the same number of letters in its Roman numeral representation as its square
  • 39 is the smallest number whose sum of digits is larger than that of its square
  • 39 is the smallest number with multiplicative persistence 3
  • 39 is the smallest number which has 3 different partitions into 3 parts with the same product
  • 39 is the least composite odd number that is the sum of the primes between its smallest and largest prime factors (39 = 3 x 13 = 3 + 5 + 7 + 11 + 13)
  • 39 is the smallest number with four X's in its Roman numerals notation XXXIX; note that five X's are impossible

Common Properties of 39

Composite
Deficient
Evil
Odd
Square-free