6643490785009 has 27 divisors (see below), whose sum is σ = 7227704699019. Its totient is φ = 6103719095760.

The previous prime is 6643490784949. The next prime is 6643490785069. The reversal of 6643490785009 is 9005870943466.

The square root of 6643490785009 is 2577497.

It is a perfect power (a square), and thus also a powerful number.

6643490785009 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (6643490784949) and next prime (6643490785069).

It can be written as a sum of positive squares in only one way, i.e., 982764909025 + 5660725875984 = 991345^2 + 2379228^2 .

It is a de Polignac number, because none of the positive numbers 2^k-6643490785009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6643490785069) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 11090969292 + ... + 11090969890.

Almost surely, 2^{6643490785009} is an apocalyptic number.

6643490785009 is the 2577497-th square number.

6643490785009 is the 1288749-th centered octagonal number.

It is an amenable number.

6643490785009 is a deficient number, since it is larger than the sum of its proper divisors (584213914010).

6643490785009 is an frugal number, since it uses more digits than its factorization.

6643490785009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1886 (or 943 counting only the distinct ones).

The product of its (nonzero) digits is 39191040, while the sum is 61.

The spelling of 6643490785009 in words is "six trillion, six hundred forty-three billion, four hundred ninety million, seven hundred eighty-five thousand, nine".