25665 has 16 divisors (see below), whose sum is σ = 43200. Its totient is φ = 12992.

The previous prime is 25657. The next prime is 25667. The reversal of 25665 is 56652.

It is not a de Polignac number, because 25665 - 2³ = 25657 is a prime.

It is a nialpdrome in base 16.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 25665.

It is not an unprimeable number, because it can be changed into a prime (25667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 406 + ... + 464.

It is an arithmetic number, because the mean of its divisors is an integer number (2700).

2²⁵⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

25665 is a deficient number, since it is larger than the sum of its proper divisors (17535).

25665 is a wasteful number, since it uses less digits than its factorization.

25665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96.

The product of its digits is 1800, while the sum is 24.

The square root of 25665 is about 160.2029962267. The cubic root of 25665 is about 29.4971748707.

The spelling of 25665 in words is "twenty-five thousand, six hundred sixty-five".