25478809 has 2 divisors, whose sum is σ = 25478810. Its totient is φ = 25478808.

The previous prime is 25478797. The next prime is 25478821. The reversal of 25478809 is 90887452.

It is a balanced prime because it is at equal distance from previous prime (25478797) and next prime (25478821).

It can be written as a sum of positive squares in only one way, i.e., 25280784 + 198025 = 5028^2 + 445^2 .

It is a cyclic number.

It is not a de Polignac number, because 25478809 - 2⁵ = 25478777 is a prime.

It is not a weakly prime, because it can be changed into another prime (25478879) 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, 12739404 + 12739405.

It is an arithmetic number, because the mean of its divisors is an integer number (12739405).

Almost surely, 2^25478809 is an apocalyptic number.

It is an amenable number.

25478809 is a deficient number, since it is larger than the sum of its proper divisors (1).

25478809 is an equidigital number, since it uses as much as digits as its factorization.

25478809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 161280, while the sum is 43.

The square root of 25478809 is about 5047.6538114257. The cubic root of 25478809 is about 294.2567096250.

The spelling of 25478809 in words is "twenty-five million, four hundred seventy-eight thousand, eight hundred nine".