• 240 can be written using four 4's:
It is a Jordan-Polya number, since it can be written as 5! ⋅ 2!.
240 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
It is a tau number, because it is divible by the number of its divisors (20).
It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.
240 is an idoneal number.
It is a plaindrome in base 13.
It is a nialpdrome in base 2, base 3, base 4, base 15 and base 16.
It is a zygodrome in base 2 and base 4.
It is a congruent number.
In principle, a polygon with 240 sides can be constructed with ruler and compass.
240 is a highly composite number, because it has more divisors than any smaller number.
240 is a superabundant number, because it has a larger abundancy index than any smaller number.
240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.
240 is a droll number since its even prime factors and its odd prime factors have the same sum.
It is an amenable number.
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
240 is a wasteful number, since it uses less digits than its factorization.
240 is an evil number, because the sum of its binary digits is even.
The square root of 240 is about 15.4919333848. The cubic root of 240 is about 6.2144650119.
Adding to 240 its reverse (42), we get a palindrome (282).