25205665 has 4 divisors (see below), whose sum is σ = 30246804. Its totient is φ = 20164528.

The previous prime is 25205651. The next prime is 25205683. The reversal of 25205665 is 56650252.

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

It can be written as a sum of positive squares in 2 ways, for example, as 11075584 + 14130081 = 3328^2 + 3759^2 .

It is a cyclic number.

It is not a de Polignac number, because 25205665 - 2⁵ = 25205633 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2520562 + ... + 2520571.

It is an arithmetic number, because the mean of its divisors is an integer number (7561701).

Almost surely, 2^25205665 is an apocalyptic number.

It is an amenable number.

25205665 is a deficient number, since it is larger than the sum of its proper divisors (5041139).

25205665 is an equidigital number, since it uses as much as digits as its factorization.

25205665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5041138.

The product of its (nonzero) digits is 18000, while the sum is 31.

The square root of 25205665 is about 5020.5243750031. The cubic root of 25205665 is about 293.2014091976.

The spelling of 25205665 in words is "twenty-five million, two hundred five thousand, six hundred sixty-five".