25991365 has 4 divisors (see below), whose sum is σ = 31189644. Its totient is φ = 20793088.

The previous prime is 25991363. The next prime is 25991387. The reversal of 25991365 is 56319952.

It is a happy number.

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 6964321 + 19027044 = 2639^2 + 4362^2 .

It is a cyclic number.

It is not a de Polignac number, because 25991365 - 2¹ = 25991363 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25991363) 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 3 ways as a sum of consecutive naturals, for example, 2599132 + ... + 2599141.

It is an arithmetic number, because the mean of its divisors is an integer number (7797411).

Almost surely, 2^25991365 is an apocalyptic number.

It is an amenable number.

25991365 is a deficient number, since it is larger than the sum of its proper divisors (5198279).

25991365 is an equidigital number, since it uses as much as digits as its factorization.

25991365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5198278.

The product of its digits is 72900, while the sum is 40.

The square root of 25991365 is about 5098.1727118645. The cubic root of 25991365 is about 296.2168068586.

The spelling of 25991365 in words is "twenty-five million, nine hundred ninety-one thousand, three hundred sixty-five".