6640865745 has 16 divisors (see below), whose sum is σ = 10626466560. Its totient is φ = 3541434624.

The previous prime is 6640865743. The next prime is 6640865753. The reversal of 6640865745 is 5475680466.

It is not a de Polignac number, because 6640865745 - 2¹ = 6640865743 is a prime.

It is a super-2 number, since 2×6640865745² = 88202195686228810050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6640865743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 201897 + ... + 232473.

It is an arithmetic number, because the mean of its divisors is an integer number (664154160).

Almost surely, 2^6640865745 is an apocalyptic number.

It is an amenable number.

6640865745 is a deficient number, since it is larger than the sum of its proper divisors (3985600815).

6640865745 is a wasteful number, since it uses less digits than its factorization.

6640865745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45064.

The product of its (nonzero) digits is 4838400, while the sum is 51.

The square root of 6640865745 is about 81491.5071955354. The cubic root of 6640865745 is about 1879.6409591437.

The spelling of 6640865745 in words is "six billion, six hundred forty million, eight hundred sixty-five thousand, seven hundred forty-five".