6647864 has 24 divisors (see below), whose sum is σ = 12831840. Its totient is φ = 3228768.

The previous prime is 6647831. The next prime is 6647869. The reversal of 6647864 is 4687466.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6647869) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10649 + ... + 11255.

It is an arithmetic number, because the mean of its divisors is an integer number (534660).

Almost surely, 2^6647864 is an apocalyptic number.

It is an amenable number.

6647864 is a deficient number, since it is larger than the sum of its proper divisors (6183976).

6647864 is a wasteful number, since it uses less digits than its factorization.

6647864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 687 (or 646 counting only the distinct ones).

The product of its digits is 193536, while the sum is 41.

The square root of 6647864 is about 2578.3452057473. The cubic root of 6647864 is about 188.0300993003.

The spelling of 6647864 in words is "six million, six hundred forty-seven thousand, eight hundred sixty-four".