25697891 has 2 divisors, whose sum is σ = 25697892. Its totient is φ = 25697890.

The previous prime is 25697887. The next prime is 25697909. The reversal of 25697891 is 19879652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25697891 - 2² = 25697887 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (25697801) 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, 12848945 + 12848946.

It is an arithmetic number, because the mean of its divisors is an integer number (12848946).

Almost surely, 2^25697891 is an apocalyptic number.

25697891 is a deficient number, since it is larger than the sum of its proper divisors (1).

25697891 is an equidigital number, since it uses as much as digits as its factorization.

25697891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 272160, while the sum is 47.

The square root of 25697891 is about 5069.3087299947. The cubic root of 25697891 is about 295.0977020057.

The spelling of 25697891 in words is "twenty-five million, six hundred ninety-seven thousand, eight hundred ninety-one".