25985863261 has 4 divisors (see below), whose sum is σ = 25986853152. Its totient is φ = 25984873372.

The previous prime is 25985863237. The next prime is 25985863291. The reversal of 25985863261 is 16236858952.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25985863261 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 (25985863231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 454465 + ... + 508438.

It is an arithmetic number, because the mean of its divisors is an integer number (6496713288).

Almost surely, 2^25985863261 is an apocalyptic number.

It is an amenable number.

25985863261 is a deficient number, since it is larger than the sum of its proper divisors (989891).

25985863261 is an equidigital number, since it uses as much as digits as its factorization.

25985863261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 989890.

The product of its digits is 6220800, while the sum is 55.

The spelling of 25985863261 in words is "twenty-five billion, nine hundred eighty-five million, eight hundred sixty-three thousand, two hundred sixty-one".