6687389 has 2 divisors, whose sum is σ = 6687390. Its totient is φ = 6687388.

The previous prime is 6687383. The next prime is 6687391. The reversal of 6687389 is 9837866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6461764 + 225625 = 2542^2 + 475^2 .

It is a cyclic number.

It is not a de Polignac number, because 6687389 - 2⁸ = 6687133 is a prime.

Together with 6687391, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6687383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3343694 + 3343695.

It is an arithmetic number, because the mean of its divisors is an integer number (3343695).

Almost surely, 2^6687389 is an apocalyptic number.

It is an amenable number.

6687389 is a deficient number, since it is larger than the sum of its proper divisors (1).

6687389 is an equidigital number, since it uses as much as digits as its factorization.

6687389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 435456, while the sum is 47.

The square root of 6687389 is about 2585.9986465580. The cubic root of 6687389 is about 188.4020086995.

The spelling of 6687389 in words is "six million, six hundred eighty-seven thousand, three hundred eighty-nine".