25356881617 has 2 divisors, whose sum is σ = 25356881618. Its totient is φ = 25356881616.

The previous prime is 25356881609. The next prime is 25356881677. The reversal of 25356881617 is 71618865352.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24536402881 + 820478736 = 156641^2 + 28644^2 .

It is a cyclic number.

It is not a de Polignac number, because 25356881617 - 2³ = 25356881609 is a prime.

It is not a weakly prime, because it can be changed into another prime (25356881677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12678440808 + 12678440809.

It is an arithmetic number, because the mean of its divisors is an integer number (12678440809).

Almost surely, 2^25356881617 is an apocalyptic number.

It is an amenable number.

25356881617 is a deficient number, since it is larger than the sum of its proper divisors (1).

25356881617 is an equidigital number, since it uses as much as digits as its factorization.

25356881617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2419200, while the sum is 52.

The spelling of 25356881617 in words is "twenty-five billion, three hundred fifty-six million, eight hundred eighty-one thousand, six hundred seventeen".