6531640 has 32 divisors (see below), whose sum is σ = 14773680. Its totient is φ = 2598912.

The previous prime is 6531619. The next prime is 6531643. The reversal of 6531640 is 461356.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6531643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11032 + ... + 11608.

Almost surely, 2^6531640 is an apocalyptic number.

It is an amenable number.

6531640 is an abundant number, since it is smaller than the sum of its proper divisors (8242040).

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

6531640 is a wasteful number, since it uses less digits than its factorization.

6531640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 871 (or 867 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 6531640 is about 2555.7073384877. The cubic root of 6531640 is about 186.9278797643.

Adding to 6531640 its reverse (461356), we get a palindrome (6992996).

It can be divided in two parts, 65316 and 40, that added together give a palindrome (65356).

The spelling of 6531640 in words is "six million, five hundred thirty-one thousand, six hundred forty".