6444240664 has 32 divisors (see below), whose sum is σ = 12170388240. Its totient is φ = 3198873600.

The previous prime is 6444240581. The next prime is 6444240667. The reversal of 6444240664 is 4660424446.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6444240667) 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, 800419 + ... + 808429.

Almost surely, 2^6444240664 is an apocalyptic number.

It is an amenable number.

6444240664 is a deficient number, since it is larger than the sum of its proper divisors (5726147576).

6444240664 is a wasteful number, since it uses less digits than its factorization.

6444240664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8731 (or 8727 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 40.

The square root of 6444240664 is about 80276.0279535554. The cubic root of 6444240664 is about 1860.9037755290.

The spelling of 6444240664 in words is "six billion, four hundred forty-four million, two hundred forty thousand, six hundred sixty-four".