25806 has 32 divisors (see below), whose sum is σ = 62208. Its totient is φ = 7040.

The previous prime is 25801. The next prime is 25819. The reversal of 25806 is 60852.

It is a happy number.

25806 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a nialpdrome in base 13.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 25806.

It is not an unprimeable number, because it can be changed into a prime (25801) by changing a digit.

25806 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1111 + ... + 1133.

It is an arithmetic number, because the mean of its divisors is an integer number (1944).

2²⁵⁸⁰⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25806, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31104).

25806 is an abundant number, since it is smaller than the sum of its proper divisors (36402).

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

25806 is a wasteful number, since it uses less digits than its factorization.

25806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 25806 is about 160.6424601405. The cubic root of 25806 is about 29.5510940642.

The spelling of 25806 in words is "twenty-five thousand, eight hundred six".