25803566779 has 4 divisors (see below), whose sum is σ = 25860030184. Its totient is φ = 25747103376.

The previous prime is 25803566749. The next prime is 25803566783. The reversal of 25803566779 is 97766530852.

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

It is a cyclic number.

It is not a de Polignac number, because 25803566779 - 2¹³ = 25803558587 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25803566729) 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, 28231017 + ... + 28231930.

It is an arithmetic number, because the mean of its divisors is an integer number (6465007546).

Almost surely, 2^25803566779 is an apocalyptic number.

25803566779 is a deficient number, since it is larger than the sum of its proper divisors (56463405).

25803566779 is an equidigital number, since it uses as much as digits as its factorization.

25803566779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56463404.

The product of its (nonzero) digits is 19051200, while the sum is 58.

The spelling of 25803566779 in words is "twenty-five billion, eight hundred three million, five hundred sixty-six thousand, seven hundred seventy-nine".