25856908091 has 16 divisors (see below), whose sum is σ = 29858500800. Its totient is φ = 21932476800.

The previous prime is 25856908087. The next prime is 25856908127. The reversal of 25856908091 is 19080965852.

It is a cyclic number.

It is not a de Polignac number, because 25856908091 - 2² = 25856908087 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25856908001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1573385 + ... + 1589733.

It is an arithmetic number, because the mean of its divisors is an integer number (1866156300).

Almost surely, 2^25856908091 is an apocalyptic number.

25856908091 is a deficient number, since it is larger than the sum of its proper divisors (4001592709).

25856908091 is a wasteful number, since it uses less digits than its factorization.

25856908091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18694.

The product of its (nonzero) digits is 1555200, while the sum is 53.

The spelling of 25856908091 in words is "twenty-five billion, eight hundred fifty-six million, nine hundred eight thousand, ninety-one".