6689491 has 2 divisors, whose sum is σ = 6689492. Its totient is φ = 6689490.

The previous prime is 6689429. The next prime is 6689497. The reversal of 6689491 is 1949866.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6689491 - 2⁷ = 6689363 is a prime.

It is not a weakly prime, because it can be changed into another prime (6689497) 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, 3344745 + 3344746.

It is an arithmetic number, because the mean of its divisors is an integer number (3344746).

Almost surely, 2^6689491 is an apocalyptic number.

6689491 is a deficient number, since it is larger than the sum of its proper divisors (1).

6689491 is an equidigital number, since it uses as much as digits as its factorization.

6689491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 93312, while the sum is 43.

The square root of 6689491 is about 2586.4050340192. The cubic root of 6689491 is about 188.4217463249.

The spelling of 6689491 in words is "six million, six hundred eighty-nine thousand, four hundred ninety-one".