6644664664 has 24 divisors (see below), whose sum is σ = 13694326380. Its totient is φ = 3020301680.

The previous prime is 6644664599. The next prime is 6644664671. The reversal of 6644664664 is 4664664466.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 3431194 + ... + 3433129.

Almost surely, 2^6644664664 is an apocalyptic number.

It is an amenable number.

6644664664 is an abundant number, since it is smaller than the sum of its proper divisors (7049661716).

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

6644664664 is a wasteful number, since it uses less digits than its factorization.

6644664664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6864351 (or 6864336 counting only the distinct ones).

The product of its digits is 11943936, while the sum is 52.

The square root of 6644664664 is about 81514.8125434881. The cubic root of 6644664664 is about 1879.9993081331. Note that the first 3 decimals are identical.

The spelling of 6644664664 in words is "six billion, six hundred forty-four million, six hundred sixty-four thousand, six hundred sixty-four".