25685867789 has 2 divisors, whose sum is σ = 25685867790. Its totient is φ = 25685867788.

The previous prime is 25685867777. The next prime is 25685867797. The reversal of 25685867789 is 98776858652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25069338889 + 616528900 = 158333^2 + 24830^2 .

It is a cyclic number.

It is not a de Polignac number, because 25685867789 - 2²⁸ = 25417432333 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25685267789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12842933894 + 12842933895.

It is an arithmetic number, because the mean of its divisors is an integer number (12842933895).

Almost surely, 2^25685867789 is an apocalyptic number.

It is an amenable number.

25685867789 is a deficient number, since it is larger than the sum of its proper divisors (1).

25685867789 is an equidigital number, since it uses as much as digits as its factorization.

25685867789 is an evil number, because the sum of its binary digits is even.

The product of its digits is 406425600, while the sum is 71.

The spelling of 25685867789 in words is "twenty-five billion, six hundred eighty-five million, eight hundred sixty-seven thousand, seven hundred eighty-nine".