25806397 has 2 divisors, whose sum is σ = 25806398. Its totient is φ = 25806396.

The previous prime is 25806379. The next prime is 25806401. The reversal of 25806397 is 79360852.

Together with previous prime (25806379) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19945156 + 5861241 = 4466^2 + 2421^2 .

It is a cyclic number.

It is not a de Polignac number, because 25806397 - 2⁷ = 25806269 is a prime.

It is a super-2 number, since 2×25806397² = 1331940252243218, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25806307) 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, 12903198 + 12903199.

It is an arithmetic number, because the mean of its divisors is an integer number (12903199).

Almost surely, 2^25806397 is an apocalyptic number.

It is an amenable number.

25806397 is a deficient number, since it is larger than the sum of its proper divisors (1).

25806397 is an equidigital number, since it uses as much as digits as its factorization.

25806397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 40.

The square root of 25806397 is about 5079.9997047244. Note that the first 3 decimals coincide. The cubic root of 25806397 is about 295.5124560166.

The spelling of 25806397 in words is "twenty-five million, eight hundred six thousand, three hundred ninety-seven".