25765991 has 4 divisors (see below), whose sum is σ = 26597184. Its totient is φ = 24934800.

The previous prime is 25765981. The next prime is 25766017. The reversal of 25765991 is 19956752.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25765991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25765951) 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, 415550 + ... + 415611.

It is an arithmetic number, because the mean of its divisors is an integer number (6649296).

Almost surely, 2^25765991 is an apocalyptic number.

25765991 is a deficient number, since it is larger than the sum of its proper divisors (831193).

25765991 is an equidigital number, since it uses as much as digits as its factorization.

25765991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 831192.

The product of its digits is 170100, while the sum is 44.

The square root of 25765991 is about 5076.0211780488. The cubic root of 25765991 is about 295.3581439727.

The spelling of 25765991 in words is "twenty-five million, seven hundred sixty-five thousand, nine hundred ninety-one".