25644561 has 8 divisors (see below), whose sum is σ = 34674624. Its totient is φ = 16855440.

The previous prime is 25644529. The next prime is 25644581. The reversal of 25644561 is 16544652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 25644561 - 2⁵ = 25644529 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (25644511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59986 + ... + 60411.

It is an arithmetic number, because the mean of its divisors is an integer number (4334328).

Almost surely, 2^25644561 is an apocalyptic number.

It is an amenable number.

25644561 is a deficient number, since it is larger than the sum of its proper divisors (9030063).

25644561 is a wasteful number, since it uses less digits than its factorization.

25644561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120471.

The product of its digits is 28800, while the sum is 33.

The square root of 25644561 is about 5064.0459121141. The cubic root of 25644561 is about 294.8934250663.

Subtracting from 25644561 its reverse (16544652), we obtain a palindrome (9099909).

The spelling of 25644561 in words is "twenty-five million, six hundred forty-four thousand, five hundred sixty-one".