25561509408 has 54 divisors (see below), whose sum is σ = 72698258997. Its totient is φ = 8519598720.

The previous prime is 25561509403. The next prime is 25561509427. The reversal of 25561509408 is 80490516552.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

25561509408 is a `hidden beast` number, since 2 + 556 + 1 + 5 + 0 + 94 + 0 + 8 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 24753358224 + 808151184 = 157332^2 + 28428^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=113052.

It is a super-3 number, since 3×25561509408³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (25561509403) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2708538 + ... + 2717958.

Almost surely, 2^25561509408 is an apocalyptic number.

It is an amenable number.

25561509408 is an abundant number, since it is smaller than the sum of its proper divisors (47136749589).

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

25561509408 is an frugal number, since it uses more digits than its factorization.

25561509408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18858 (or 9426 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 45.

The spelling of 25561509408 in words is "twenty-five billion, five hundred sixty-one million, five hundred nine thousand, four hundred eight".