6509640 has 64 divisors (see below), whose sum is σ = 20684160. Its totient is φ = 1633280.

The previous prime is 6509617. The next prime is 6509677. The reversal of 6509640 is 469056.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 6509598 and 6509607.

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, 445 + ... + 3635.

It is an arithmetic number, because the mean of its divisors is an integer number (323190).

Almost surely, 2^6509640 is an apocalyptic number.

6509640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6509640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10342080).

6509640 is an abundant number, since it is smaller than the sum of its proper divisors (14174520).

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

6509640 is a wasteful number, since it uses less digits than its factorization.

6509640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3222 (or 3218 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 6509640 is about 2551.3996158971. The cubic root of 6509640 is about 186.7177722882.

The spelling of 6509640 in words is "six million, five hundred nine thousand, six hundred forty".