6445989741809 has 2 divisors, whose sum is σ = 6445989741810. Its totient is φ = 6445989741808.

The previous prime is 6445989741769. The next prime is 6445989741859. The reversal of 6445989741809 is 9081479895446.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6395512234225 + 50477507584 = 2528935^2 + 224672^2 .

It is a cyclic number.

It is not a de Polignac number, because 6445989741809 - 2⁸ = 6445989741553 is a prime.

It is not a weakly prime, because it can be changed into another prime (6445989741859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3222994870904 + 3222994870905.

It is an arithmetic number, because the mean of its divisors is an integer number (3222994870905).

Almost surely, 2^{6445989741809} is an apocalyptic number.

It is an amenable number.

6445989741809 is a deficient number, since it is larger than the sum of its proper divisors (1).

6445989741809 is an equidigital number, since it uses as much as digits as its factorization.

6445989741809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 627056640, while the sum is 74.

The spelling of 6445989741809 in words is "six trillion, four hundred forty-five billion, nine hundred eighty-nine million, seven hundred forty-one thousand, eight hundred nine".