25817 has 4 divisors (see below), whose sum is σ = 28176. Its totient is φ = 23460.

The previous prime is 25801. The next prime is 25819. The reversal of 25817 is 71852.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 25817 - 2⁴ = 25801 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 25792 and 25801.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 25817.

It is not an unprimeable number, because it can be changed into a prime (25819) 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, 1163 + ... + 1184.

It is an arithmetic number, because the mean of its divisors is an integer number (7044).

2²⁵⁸¹⁷ is an apocalyptic number.

It is an amenable number.

25817 is a deficient number, since it is larger than the sum of its proper divisors (2359).

25817 is a wasteful number, since it uses less digits than its factorization.

25817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2358.

The product of its digits is 560, while the sum is 23.

The square root of 25817 is about 160.6766940163. The cubic root of 25817 is about 29.5552922592. Note that the first 3 decimals are identical.

The spelling of 25817 in words is "twenty-five thousand, eight hundred seventeen".