25431563881 has 2 divisors, whose sum is σ = 25431563882. Its totient is φ = 25431563880.

The previous prime is 25431563819. The next prime is 25431563909. The reversal of 25431563881 is 18836513452.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24354411481 + 1077152400 = 156059^2 + 32820^2 .

It is a cyclic number.

It is not a de Polignac number, because 25431563881 - 2⁷ = 25431563753 is a prime.

It is a super-2 number, since 2×25431563881² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (25431563081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12715781940 + 12715781941.

It is an arithmetic number, because the mean of its divisors is an integer number (12715781941).

Almost surely, 2^25431563881 is an apocalyptic number.

It is an amenable number.

25431563881 is a deficient number, since it is larger than the sum of its proper divisors (1).

25431563881 is an equidigital number, since it uses as much as digits as its factorization.

25431563881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 691200, while the sum is 46.

The spelling of 25431563881 in words is "twenty-five billion, four hundred thirty-one million, five hundred sixty-three thousand, eight hundred eighty-one".