6649865439 has 16 divisors (see below), whose sum is σ = 10142694912. Its totient is φ = 3796335648.

The previous prime is 6649865437. The next prime is 6649865473. The reversal of 6649865439 is 9345689466.

It is not a de Polignac number, because 6649865439 - 2¹ = 6649865437 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6649865437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 126624 + ... + 171269.

It is an arithmetic number, because the mean of its divisors is an integer number (633918432).

Almost surely, 2^6649865439 is an apocalyptic number.

6649865439 is a deficient number, since it is larger than the sum of its proper divisors (3492829473).

6649865439 is a wasteful number, since it uses less digits than its factorization.

6649865439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 298966.

The product of its digits is 33592320, while the sum is 60.

The square root of 6649865439 is about 81546.7071009002. The cubic root of 6649865439 is about 1880.4896716588.

The spelling of 6649865439 in words is "six billion, six hundred forty-nine million, eight hundred sixty-five thousand, four hundred thirty-nine".