6649664 has 28 divisors (see below), whose sum is σ = 15081504. Its totient is φ = 2849664.

The previous prime is 6649661. The next prime is 6649681. The reversal of 6649664 is 4669466.

It is a tau number, because it is divible by the number of its divisors (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6649661) 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 3 ways as a sum of consecutive naturals, for example, 6974 + ... + 7869.

Almost surely, 2^6649664 is an apocalyptic number.

6649664 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

6649664 is an abundant number, since it is smaller than the sum of its proper divisors (8431840).

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

6649664 is a wasteful number, since it uses less digits than its factorization.

6649664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14862 (or 14852 counting only the distinct ones).

The product of its digits is 186624, while the sum is 41.

The square root of 6649664 is about 2578.6942432169. The cubic root of 6649664 is about 188.0470683416.

The spelling of 6649664 in words is "six million, six hundred forty-nine thousand, six hundred sixty-four".