25981495091 has 4 divisors (see below), whose sum is σ = 25993689384. Its totient is φ = 25969300800.

The previous prime is 25981495087. The next prime is 25981495093. The reversal of 25981495091 is 19059418952.

It is a happy number.

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 25981495091 - 2² = 25981495087 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25981495093) 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, 6093950 + ... + 6098211.

It is an arithmetic number, because the mean of its divisors is an integer number (6498422346).

Almost surely, 2^25981495091 is an apocalyptic number.

25981495091 is a deficient number, since it is larger than the sum of its proper divisors (12194293).

25981495091 is a wasteful number, since it uses less digits than its factorization.

25981495091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12194292.

The product of its (nonzero) digits is 1166400, while the sum is 53.

The spelling of 25981495091 in words is "twenty-five billion, nine hundred eighty-one million, four hundred ninety-five thousand, ninety-one".