• 48 can be written using four 4's:
It is a Jordan-Polya number, since it can be written as 4! ⋅ 2!.
It is a double factorial (48 = 6 !! = 2 ⋅ 4 ⋅ 6 ).
48 is nontrivially palindromic in base 7, base 11 and base 15.
48 is an esthetic number in base 3, because in such base its adjacent digits differ by 1.
It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.
It is a nude number because it is divisible by every one of its digits.
48 is an idoneal number.
It is an Ulam number.
48 is a nontrivial repdigit in base 7, base 11 and base 15.
It is a plaindrome in base 7, base 10, base 11, base 13, base 14 and base 15.
It is a nialpdrome in base 2, base 4, base 7, base 8, base 9, base 11, base 12, base 15 and base 16.
It is a zygodrome in base 2, base 7, base 11 and base 15.
A polygon with 48 sides can be constructed with ruler and compass.
48 is a highly composite number, because it has more divisors than any smaller number.
48 is a superabundant number, because it has a larger abundancy index than any smaller number.
It is an amenable number.
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
48 is a wasteful number, since it uses less digits than its factorization.
48 is an evil number, because the sum of its binary digits is even.
The square root of 48 is about 6.9282032303. The cubic root of 48 is about 3.6342411857.
Subtracting from 48 its sum of digits (12), we obtain a triangular number (36 = T8).
Multiplying 48 by its sum of digits (12), we get a square (576 = 242).
Subtracting from 48 its product of digits (32), we obtain a 4-th power (16 = 24).
Subtracting 48 from its reverse (84), we obtain a triangular number (36 = T8).