6689909 has 2 divisors, whose sum is σ = 6689910. Its totient is φ = 6689908.

The previous prime is 6689873. The next prime is 6689971. The reversal of 6689909 is 9099866.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5189284 + 1500625 = 2278^2 + 1225^2 .

It is a cyclic number.

It is not a de Polignac number, because 6689909 - 2¹² = 6685813 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6689989) 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, 3344954 + 3344955.

It is an arithmetic number, because the mean of its divisors is an integer number (3344955).

Almost surely, 2^6689909 is an apocalyptic number.

It is an amenable number.

6689909 is a deficient number, since it is larger than the sum of its proper divisors (1).

6689909 is an equidigital number, since it uses as much as digits as its factorization.

6689909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 209952, while the sum is 47.

The square root of 6689909 is about 2586.4858398994. The cubic root of 6689909 is about 188.4256708213.

The spelling of 6689909 in words is "six million, six hundred eighty-nine thousand, nine hundred nine".