25998691 has 2 divisors, whose sum is σ = 25998692. Its totient is φ = 25998690.

The previous prime is 25998689. The next prime is 25998697. The reversal of 25998691 is 19689952.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25998691 - 2¹ = 25998689 is a prime.

Together with 25998689, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (25998697) 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, 12999345 + 12999346.

It is an arithmetic number, because the mean of its divisors is an integer number (12999346).

Almost surely, 2^25998691 is an apocalyptic number.

25998691 is a deficient number, since it is larger than the sum of its proper divisors (1).

25998691 is an equidigital number, since it uses as much as digits as its factorization.

25998691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 349920, while the sum is 49.

The square root of 25998691 is about 5098.8911539667. The cubic root of 25998691 is about 296.2446350812.

The spelling of 25998691 in words is "twenty-five million, nine hundred ninety-eight thousand, six hundred ninety-one".