25565 has 4 divisors (see below), whose sum is σ = 30684. Its totient is φ = 20448.

The previous prime is 25561. The next prime is 25577. The reversal of 25565 is 56552.

25565 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3364 + 22201 = 58^2 + 149^2 .

It is a cyclic number.

It is not a de Polignac number, because 25565 - 2² = 25561 is a prime.

It is a Duffinian number.

25565 is strictly pandigital in base 6.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 25565.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2552 + ... + 2561.

It is an arithmetic number, because the mean of its divisors is an integer number (7671).

2²⁵⁵⁶⁵ is an apocalyptic number.

It is an amenable number.

25565 is a deficient number, since it is larger than the sum of its proper divisors (5119).

25565 is an equidigital number, since it uses as much as digits as its factorization.

25565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5118.

The product of its digits is 1500, while the sum is 23.

The square root of 25565 is about 159.8905875904. The cubic root of 25565 is about 29.4588144986.

The spelling of 25565 in words is "twenty-five thousand, five hundred sixty-five".