Adding to 7521 its reverse (1257), we get a palindrome (8778).
It is a happy number.
7521 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.
It is a sphenic number, since it is the product of 3 distinct primes.
It is a plaindrome in base 13 and base 15.
It is a nialpdrome in base 10.
It is a self number, because there is not a number n which added to its sum of digits gives 7521.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 7521.
27521 is an apocalyptic number.
It is an amenable number.
7521 is a wasteful number, since it uses less digits than its factorization.
7521 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 135.
The square root of 7521 is about 86.7236991831. The cubic root of 7521 is about 19.5925905632.
The spelling of 7521 in words is "seven thousand, five hundred twenty-one".