105

105 is an integer equal to 7!!.
Its prime factorization is 3 × 5 × 7.
It is part of a Ruth–Aaron pair with 104OEIS, Sequence A006145 (accessed 2021-02-09) using the formulation involving sums of prime factors.
It is the first .
The 105th is the first cyclotomic polynomial containing coefficients with absolute value larger than 1.
It is the smallest odd number, for which the is larger than the .
==Sources==
Category:Numbers
Category:Class 1
Category:Factorial numbers
Category:Non-powers
Category:Numbers with 3 digits
Category:Odd numbers
Category:Unnamed numbers with googological uses