6891887 has 2 divisors, whose sum is σ = 6891888. Its totient is φ = 6891886.

The previous prime is 6891883. The next prime is 6891901. The reversal of 6891887 is 7881986.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6891887 - 2² = 6891883 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6891883) 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, 3445943 + 3445944.

It is an arithmetic number, because the mean of its divisors is an integer number (3445944).

Almost surely, 2^6891887 is an apocalyptic number.

6891887 is a deficient number, since it is larger than the sum of its proper divisors (1).

6891887 is an equidigital number, since it uses as much as digits as its factorization.

6891887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 193536, while the sum is 47.

The square root of 6891887 is about 2625.2403699471. The cubic root of 6891887 is about 190.3031817010.

Subtracting 6891887 from its reverse (7881986), we obtain a palindrome (990099).

The spelling of 6891887 in words is "six million, eight hundred ninety-one thousand, eight hundred eighty-seven".