25681816548 has 18 divisors (see below), whose sum is σ = 64917925254. Its totient is φ = 8560605504.

The previous prime is 25681816541. The next prime is 25681816577. The reversal of 25681816548 is 84561818652.

25681816548 is a `hidden beast` number, since 2 + 5 + 6 + 81 + 8 + 16 + 548 = 666.

It can be written as a sum of positive squares in only one way, i.e., 22613542884 + 3068273664 = 150378^2 + 55392^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 25681816494 and 25681816503.

It is not an unprimeable number, because it can be changed into a prime (25681816541) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 356691861 + ... + 356691932.

It is an arithmetic number, because the mean of its divisors is an integer number (3606551403).

Almost surely, 2^25681816548 is an apocalyptic number.

It is an amenable number.

25681816548 is an abundant number, since it is smaller than the sum of its proper divisors (39236108706).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25681816548 is a wasteful number, since it uses less digits than its factorization.

25681816548 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 713383803 (or 713383798 counting only the distinct ones).

The product of its digits is 3686400, while the sum is 54.

The spelling of 25681816548 in words is "twenty-five billion, six hundred eighty-one million, eight hundred sixteen thousand, five hundred forty-eight".