6520640 has 112 divisors (see below), whose sum is σ = 18434304. Its totient is φ = 2150400.

The previous prime is 6520609. The next prime is 6520691. The reversal of 6520640 is 460256.

It is a tau number, because it is divible by the number of its divisors (112).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 91805 + ... + 91875.

It is an arithmetic number, because the mean of its divisors is an integer number (164592).

Almost surely, 2^6520640 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 6520640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9217152).

6520640 is an abundant number, since it is smaller than the sum of its proper divisors (11913664).

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

6520640 is a wasteful number, since it uses less digits than its factorization.

6520640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136 (or 126 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 6520640 is about 2553.5543855575. The cubic root of 6520640 is about 186.8228850998.

Adding to 6520640 its reverse (460256), we get a palindrome (6980896).

The spelling of 6520640 in words is "six million, five hundred twenty thousand, six hundred forty".