6639449 has 2 divisors, whose sum is σ = 6639450. Its totient is φ = 6639448.

The previous prime is 6639439. The next prime is 6639467. The reversal of 6639449 is 9449366.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6553600 + 85849 = 2560^2 + 293^2 .

It is a cyclic number.

It is not a de Polignac number, because 6639449 - 2¹² = 6635353 is a prime.

It is a Sophie Germain prime.

It is an Ulam number.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (6639439) 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 as a sum of consecutive naturals, namely, 3319724 + 3319725.

It is an arithmetic number, because the mean of its divisors is an integer number (3319725).

Almost surely, 2^6639449 is an apocalyptic number.

It is an amenable number.

6639449 is a deficient number, since it is larger than the sum of its proper divisors (1).

6639449 is an equidigital number, since it uses as much as digits as its factorization.

6639449 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 139968, while the sum is 41.

The square root of 6639449 is about 2576.7128283920. The cubic root of 6639449 is about 187.9507283735.

The spelling of 6639449 in words is "six million, six hundred thirty-nine thousand, four hundred forty-nine".