25997861 has 2 divisors, whose sum is σ = 25997862. Its totient is φ = 25997860.

The previous prime is 25997849. The next prime is 25997869. The reversal of 25997861 is 16879952.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18653761 + 7344100 = 4319^2 + 2710^2 .

It is a cyclic number.

It is not a de Polignac number, because 25997861 - 2¹⁰ = 25996837 is a 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 (25997869) 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, 12998930 + 12998931.

It is an arithmetic number, because the mean of its divisors is an integer number (12998931).

Almost surely, 2^25997861 is an apocalyptic number.

It is an amenable number.

25997861 is a deficient number, since it is larger than the sum of its proper divisors (1).

25997861 is an equidigital number, since it uses as much as digits as its factorization.

25997861 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 25997861 is about 5098.8097630722. The cubic root of 25997861 is about 296.2414825422.

The spelling of 25997861 in words is "twenty-five million, nine hundred ninety-seven thousand, eight hundred sixty-one".