25555811197 has 4 divisors (see below), whose sum is σ = 29206641376. Its totient is φ = 21904981020.

The previous prime is 25555811191. The next prime is 25555811219. The reversal of 25555811197 is 79111855552.

It is a happy number.

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 25555811197 - 2³ = 25555811189 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 25555811197.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25555811191) 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, 1825415079 + ... + 1825415092.

It is an arithmetic number, because the mean of its divisors is an integer number (7301660344).

Almost surely, 2^25555811197 is an apocalyptic number.

It is an amenable number.

25555811197 is a deficient number, since it is larger than the sum of its proper divisors (3650830179).

25555811197 is an equidigital number, since it uses as much as digits as its factorization.

25555811197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3650830178.

The product of its digits is 630000, while the sum is 49.

The spelling of 25555811197 in words is "twenty-five billion, five hundred fifty-five million, eight hundred eleven thousand, one hundred ninety-seven".