25561386479 has 4 divisors (see below), whose sum is σ = 25562308200. Its totient is φ = 25560464760.

The previous prime is 25561386457. The next prime is 25561386517. The reversal of 25561386479 is 97468316552.

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 25561386479 - 2¹⁶ = 25561320943 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25561386449) 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, 417929 + ... + 475170.

It is an arithmetic number, because the mean of its divisors is an integer number (6390577050).

Almost surely, 2^25561386479 is an apocalyptic number.

25561386479 is a deficient number, since it is larger than the sum of its proper divisors (921721).

25561386479 is an equidigital number, since it uses as much as digits as its factorization.

25561386479 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 921720.

The product of its digits is 10886400, while the sum is 56.

The spelling of 25561386479 in words is "twenty-five billion, five hundred sixty-one million, three hundred eighty-six thousand, four hundred seventy-nine".