25881781889 has 4 divisors (see below), whose sum is σ = 25882144260. Its totient is φ = 25881419520.

The previous prime is 25881781843. The next prime is 25881781907. The reversal of 25881781889 is 98818718852.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5478516289 + 20403265600 = 74017^2 + 142840^2 .

It is a cyclic number.

It is not a de Polignac number, because 25881781889 - 2⁸ = 25881781633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25881781489) 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, 34424 + ... + 230105.

It is an arithmetic number, because the mean of its divisors is an integer number (6470536065).

Almost surely, 2^25881781889 is an apocalyptic number.

It is an amenable number.

25881781889 is a deficient number, since it is larger than the sum of its proper divisors (362371).

25881781889 is an equidigital number, since it uses as much as digits as its factorization.

25881781889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362370.

The product of its digits is 20643840, while the sum is 65.

The spelling of 25881781889 in words is "twenty-five billion, eight hundred eighty-one million, seven hundred eighty-one thousand, eight hundred eighty-nine".