55 (number)

55 (fifty-five) is the natural number following 54 and preceding 56.

55 is: 55 is also the 19th semiprime and the 15th squarefree semiprime,[6][7] as well as the 32nd nontotient number (including odd numbers > 1)[8] the 36th arithmetic number,[9] the 38th composite number[10] (where the abundance of 55 = - 38),[11] the 43rd deficient number,[12] the 45th trapezoidal number,[13] and the 49th polite number.

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