6544240 has 40 divisors (see below), whose sum is σ = 15333840. Its totient is φ = 2597376.

The previous prime is 6544217. The next prime is 6544243. The reversal of 6544240 is 424456.

It is a tau number, because it is divible by the number of its divisors (40).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6544243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14092 + ... + 14548.

It is an arithmetic number, because the mean of its divisors is an integer number (383346).

Almost surely, 2^6544240 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 6544240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7666920).

6544240 is an abundant number, since it is smaller than the sum of its proper divisors (8789600).

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

6544240 is a wasteful number, since it uses less digits than its factorization.

6544240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 649 (or 643 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 25.

The square root of 6544240 is about 2558.1712217911. The cubic root of 6544240 is about 187.0480016325.

Adding to 6544240 its reverse (424456), we get a palindrome (6968696).

The spelling of 6544240 in words is "six million, five hundred forty-four thousand, two hundred forty".