• 75 can be written using four 4's:
• 752 = 5625 is the smallest square that contains exactly two digits '5'.
75 is nontrivially palindromic in base 14.
75 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.
75 is a repfigit number.
It is a Duffinian number.
75 is strictly pandigital in base 4.
75 is a lucky number.
75 is a nontrivial repdigit in base 14.
It is a plaindrome in base 7, base 8, base 11, base 13, base 14 and base 16.
It is a nialpdrome in base 3, base 5, base 9, base 10, base 12, base 14 and base 15.
It is a zygodrome in base 14.
It is a self number, because there is not a number n which added to its sum of digits gives 75.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 75.
75 is the 5-th nonagonal number.
75 is a wasteful number, since it uses less digits than its factorization.
75 is an evil number, because the sum of its binary digits is even.
The square root of 75 is about 8.6602540378. The cubic root of 75 is about 4.2171633265.
Multiplying 75 by its sum of digits (12), we get a square (900 = 302).