6525 has 18 divisors (see below), whose sum is σ = 12090. Its totient is φ = 3360.

The previous prime is 6521. The next prime is 6529. The reversal of 6525 is 5256.

Added to its reverse (5256) it gives a triangular number (11781 = T₁₅₃).

6525 = T₅ + T₆ + ... + T₃₃.

It is an interprime number because it is at equal distance from previous prime (6521) and next prime (6529).

It can be written as a sum of positive squares in 3 ways, for example, as 441 + 6084 = 21^2 + 78^2 .

It is not a de Polignac number, because 6525 - 2² = 6521 is a prime.

It is an Ulam number.

It is an alternating number because its digits alternate between even and odd.

6525 is an undulating number in base 12.

It is a nialpdrome in base 9.

It is a junction number, because it is equal to n+sod(n) for n = 6498 and 6507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6521) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 211 + ... + 239.

It is an amenable number.

6525 is a deficient number, since it is larger than the sum of its proper divisors (5565).

6525 is a wasteful number, since it uses less digits than its factorization.

6525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45 (or 37 counting only the distinct ones).

The product of its digits is 300, while the sum is 18.

The square root of 6525 is about 80.7774721070. Note that the first 3 decimals coincide. The cubic root of 6525 is about 18.6864515282.

Adding to 6525 its reverse (5256), we get a triangular number (11781 = T₁₅₃).

The spelling of 6525 in words is "six thousand, five hundred twenty-five".