25971984197 has 4 divisors (see below), whose sum is σ = 25978355520. Its totient is φ = 25965612876.

The previous prime is 25971984191. The next prime is 25971984217. The reversal of 25971984197 is 79148917952.

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 not a de Polignac number, because 25971984197 - 2²² = 25967789893 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 (25971984191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3179543 + ... + 3187700.

It is an arithmetic number, because the mean of its divisors is an integer number (6494588880).

Almost surely, 2^25971984197 is an apocalyptic number.

It is an amenable number.

25971984197 is a deficient number, since it is larger than the sum of its proper divisors (6371323).

25971984197 is an equidigital number, since it uses as much as digits as its factorization.

25971984197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6371322.

The product of its digits is 11430720, while the sum is 62.

The spelling of 25971984197 in words is "twenty-five billion, nine hundred seventy-one million, nine hundred eighty-four thousand, one hundred ninety-seven".