25605665 has 16 divisors (see below), whose sum is σ = 32088720. Its totient is φ = 19595520.

The previous prime is 25605661. The next prime is 25605677. The reversal of 25605665 is 56650652.

It can be written as a sum of positive squares in 8 ways, for example, as 4528384 + 21077281 = 2128^2 + 4591^2 .

It is not a de Polignac number, because 25605665 - 2² = 25605661 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (25605661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10151 + ... + 12419.

It is an arithmetic number, because the mean of its divisors is an integer number (2005545).

Almost surely, 2^25605665 is an apocalyptic number.

It is an amenable number.

25605665 is a deficient number, since it is larger than the sum of its proper divisors (6483055).

25605665 is a wasteful number, since it uses less digits than its factorization.

25605665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2372.

The product of its (nonzero) digits is 54000, while the sum is 35.

The square root of 25605665 is about 5060.2040472692. The cubic root of 25605665 is about 294.7442579112.

The spelling of 25605665 in words is "twenty-five million, six hundred five thousand, six hundred sixty-five".