• 720 can be written using four 4's:
720 is nontrivially palindromic in base 11.
It is a tau number, because it is divible by the number of its divisors (30).
It is an Ulam number.
720 is an undulating number in base 11.
It is a nialpdrome in base 3, base 6, base 9, base 10, base 12 and base 15.
It is a zygodrome in base 3.
It is a congruent number.
720 is a highly composite number, because it has more divisors than any smaller number.
720 is a superabundant number, because it has a larger abundancy index than any smaller number.
2720 is an apocalyptic number.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1209).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
720 is a wasteful number, since it uses less digits than its factorization.
720 is an evil number, because the sum of its binary digits is even.
The square root of 720 is about 26.8328157300. The cubic root of 720 is about 8.9628094931.
Adding to 720 its reverse (27), we get a palindrome (747).