25385978857 has 2 divisors, whose sum is σ = 25385978858. Its totient is φ = 25385978856.

The previous prime is 25385978837. The next prime is 25385978921. The reversal of 25385978857 is 75887958352.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17291198016 + 8094780841 = 131496^2 + 89971^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25385978857 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 25385978792 and 25385978801.

It is not a weakly prime, because it can be changed into another prime (25385978837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12692989428 + 12692989429.

It is an arithmetic number, because the mean of its divisors is an integer number (12692989429).

Almost surely, 2^25385978857 is an apocalyptic number.

It is an amenable number.

25385978857 is a deficient number, since it is larger than the sum of its proper divisors (1).

25385978857 is an equidigital number, since it uses as much as digits as its factorization.

25385978857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 169344000, while the sum is 67.

The spelling of 25385978857 in words is "twenty-five billion, three hundred eighty-five million, nine hundred seventy-eight thousand, eight hundred fifty-seven".