25868715809 has 4 divisors (see below), whose sum is σ = 25869512004. Its totient is φ = 25867919616.

The previous prime is 25868715787. The next prime is 25868715827. The reversal of 25868715809 is 90851786852.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13032505600 + 12836210209 = 114160^2 + 113297^2 .

It is a cyclic number.

It is not a de Polignac number, because 25868715809 - 2⁸ = 25868715553 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (25868715709) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 347192 + ... + 415065.

It is an arithmetic number, because the mean of its divisors is an integer number (6467378001).

Almost surely, 2^25868715809 is an apocalyptic number.

It is an amenable number.

25868715809 is a deficient number, since it is larger than the sum of its proper divisors (796195).

25868715809 is an equidigital number, since it uses as much as digits as its factorization.

25868715809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 796194.

The product of its (nonzero) digits is 9676800, while the sum is 59.

The spelling of 25868715809 in words is "twenty-five billion, eight hundred sixty-eight million, seven hundred fifteen thousand, eight hundred nine".