25866488891 has 2 divisors, whose sum is σ = 25866488892. Its totient is φ = 25866488890.

The previous prime is 25866488881. The next prime is 25866488899. The reversal of 25866488891 is 19888466852.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 25866488891 - 2²⁶ = 25799380027 is a prime.

It is not a weakly prime, because it can be changed into another prime (25866488899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12933244445 + 12933244446.

It is an arithmetic number, because the mean of its divisors is an integer number (12933244446).

Almost surely, 2^25866488891 is an apocalyptic number.

25866488891 is a deficient number, since it is larger than the sum of its proper divisors (1).

25866488891 is an equidigital number, since it uses as much as digits as its factorization.

25866488891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 53084160, while the sum is 65.

The spelling of 25866488891 in words is "twenty-five billion, eight hundred sixty-six million, four hundred eighty-eight thousand, eight hundred ninety-one".