25564646553 has 16 divisors (see below), whose sum is σ = 34160462400. Its totient is φ = 17006008320.

The previous prime is 25564646449. The next prime is 25564646557. The reversal of 25564646553 is 35564646552.

It is not a de Polignac number, because 25564646553 - 2⁸ = 25564646297 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 25564646496 and 25564646505.

It is not an unprimeable number, because it can be changed into a prime (25564646557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2807538 + ... + 2816628.

It is an arithmetic number, because the mean of its divisors is an integer number (2135028900).

Almost surely, 2^25564646553 is an apocalyptic number.

It is an amenable number.

25564646553 is a deficient number, since it is larger than the sum of its proper divisors (8595815847).

25564646553 is a wasteful number, since it uses less digits than its factorization.

25564646553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11032.

The product of its digits is 12960000, while the sum is 51.

Subtracting 25564646553 from its reverse (35564646552), we obtain a palindrome (9999999999).

The spelling of 25564646553 in words is "twenty-five billion, five hundred sixty-four million, six hundred forty-six thousand, five hundred fifty-three".