6520 has 16 divisors (see below), whose sum is σ = 14760. Its totient is φ = 2592.

The previous prime is 6491. The next prime is 6521. The reversal of 6520 is 256.

6520 = T₃₁ + T₃₂ + ... + T₄₀.

It is an Ulam number.

It is a nialpdrome in base 3, base 9 and base 10.

It is a zygodrome in base 3 and base 9.

It is a self number, because there is not a number n which added to its sum of digits gives 6520.

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 pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42 + ... + 121.

2⁶⁵²⁰ is an apocalyptic number.

It is an amenable number.

6520 is an abundant number, since it is smaller than the sum of its proper divisors (8240).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7380).

6520 is a wasteful number, since it uses less digits than its factorization.

6520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174 (or 170 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 13.

The square root of 6520 is about 80.7465169527. The cubic root of 6520 is about 18.6816772686.

Adding to 6520 its reverse (256), we get a palindrome (6776).

The spelling of 6520 in words is "six thousand, five hundred twenty".