25586881681 has 9 divisors (see below), whose sum is σ = 25854357819. Its totient is φ = 25322149536.

The previous prime is 25586881673. The next prime is 25586881739. The reversal of 25586881681 is 18618868552.

The square root of 25586881681 is 159959.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 2599470225 + 22987411456 = 50985^2 + 151616^2 .

It is not a de Polignac number, because 25586881681 - 2³ = 25586881673 is a prime.

It is a super-2 number, since 2×25586881681² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25586881651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 16475001 + ... + 16476553.

Almost surely, 2^25586881681 is an apocalyptic number.

25586881681 is the 159959-th square number.

25586881681 is the 79980-th centered octagonal number.

It is an amenable number.

25586881681 is a deficient number, since it is larger than the sum of its proper divisors (267476138).

25586881681 is an frugal number, since it uses more digits than its factorization.

25586881681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3312 (or 1656 counting only the distinct ones).

The product of its digits is 7372800, while the sum is 58.

The spelling of 25586881681 in words is "twenty-five billion, five hundred eighty-six million, eight hundred eighty-one thousand, six hundred eighty-one".