25806643 has 2 divisors, whose sum is σ = 25806644. Its totient is φ = 25806642.

The previous prime is 25806623. The next prime is 25806647. The reversal of 25806643 is 34660852.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25806643 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 25806599 and 25806608.

It is not a weakly prime, because it can be changed into another prime (25806647) 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, 12903321 + 12903322.

It is an arithmetic number, because the mean of its divisors is an integer number (12903322).

Almost surely, 2^25806643 is an apocalyptic number.

25806643 is a deficient number, since it is larger than the sum of its proper divisors (1).

25806643 is an equidigital number, since it uses as much as digits as its factorization.

25806643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34560, while the sum is 34.

The square root of 25806643 is about 5080.0239172665. The cubic root of 25806643 is about 295.5133950065.

The spelling of 25806643 in words is "twenty-five million, eight hundred six thousand, six hundred forty-three".