25611 has 4 divisors (see below), whose sum is σ = 34152. Its totient is φ = 17072.

The previous prime is 25609. The next prime is 25621. The reversal of 25611 is 11652.

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

It is a cyclic number.

It is not a de Polignac number, because 25611 - 2¹ = 25609 is a prime.

It is a D-number.

25611 is a lucky number.

It is a plaindrome in base 7.

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (25601) 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, 4266 + ... + 4271.

It is an arithmetic number, because the mean of its divisors is an integer number (8538).

2²⁵⁶¹¹ is an apocalyptic number.

25611 is a deficient number, since it is larger than the sum of its proper divisors (8541).

25611 is an equidigital number, since it uses as much as digits as its factorization.

25611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8540.

The product of its digits is 60, while the sum is 15.

The square root of 25611 is about 160.0343713082. The cubic root of 25611 is about 29.4764726707.

It can be divided in two parts, 25 and 611, that added together give a palindrome (636).

The spelling of 25611 in words is "twenty-five thousand, six hundred eleven".