25195991 has 2 divisors, whose sum is σ = 25195992. Its totient is φ = 25195990.

The previous prime is 25195981. The next prime is 25196021. The reversal of 25195991 is 19959152.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25195991 - 2¹⁸ = 24933847 is a prime.

It is a Sophie Germain 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 (25195981) 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, 12597995 + 12597996.

It is an arithmetic number, because the mean of its divisors is an integer number (12597996).

Almost surely, 2^25195991 is an apocalyptic number.

25195991 is a deficient number, since it is larger than the sum of its proper divisors (1).

25195991 is an equidigital number, since it uses as much as digits as its factorization.

25195991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36450, while the sum is 41.

The square root of 25195991 is about 5019.5608373642. The cubic root of 25195991 is about 293.1638939090.

The spelling of 25195991 in words is "twenty-five million, one hundred ninety-five thousand, nine hundred ninety-one".