25661203235 has 4 divisors (see below), whose sum is σ = 30793443888. Its totient is φ = 20528962584.

The previous prime is 25661203223. The next prime is 25661203237. The reversal of 25661203235 is 53230216652.

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 25661203235 - 2³⁰ = 24587461411 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 25661203195 and 25661203204.

It is not an unprimeable number, because it can be changed into a prime (25661203237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2566120319 + ... + 2566120328.

It is an arithmetic number, because the mean of its divisors is an integer number (7698360972).

Almost surely, 2^25661203235 is an apocalyptic number.

25661203235 is a deficient number, since it is larger than the sum of its proper divisors (5132240653).

25661203235 is an equidigital number, since it uses as much as digits as its factorization.

25661203235 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5132240652.

The product of its (nonzero) digits is 64800, while the sum is 35.

Adding to 25661203235 its reverse (53230216652), we get a palindrome (78891419887).

The spelling of 25661203235 in words is "twenty-five billion, six hundred sixty-one million, two hundred three thousand, two hundred thirty-five".