6891691 has 2 divisors, whose sum is σ = 6891692. Its totient is φ = 6891690.

The previous prime is 6891673. The next prime is 6891713. The reversal of 6891691 is 1961986.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6891691 - 2⁹ = 6891179 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (6891601) 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, 3445845 + 3445846.

It is an arithmetic number, because the mean of its divisors is an integer number (3445846).

Almost surely, 2^6891691 is an apocalyptic number.

6891691 is a deficient number, since it is larger than the sum of its proper divisors (1).

6891691 is an equidigital number, since it uses as much as digits as its factorization.

6891691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23328, while the sum is 40.

The square root of 6891691 is about 2625.2030397666. The cubic root of 6891691 is about 190.3013776582.

The spelling of 6891691 in words is "six million, eight hundred ninety-one thousand, six hundred ninety-one".