25886991 has 16 divisors (see below), whose sum is σ = 37729664. Its totient is φ = 15691104.

The previous prime is 25886981. The next prime is 25887011. The reversal of 25886991 is 19968852.

It is a happy number.

It is not a de Polignac number, because 25886991 - 2⁹ = 25886479 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 25886991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25886921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2341 + ... + 7566.

It is an arithmetic number, because the mean of its divisors is an integer number (2358104).

Almost surely, 2^25886991 is an apocalyptic number.

25886991 is a deficient number, since it is larger than the sum of its proper divisors (11842673).

25886991 is a wasteful number, since it uses less digits than its factorization.

25886991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9990.

The product of its digits is 311040, while the sum is 48.

The square root of 25886991 is about 5087.9260018204. The cubic root of 25886991 is about 295.8197671665.

The spelling of 25886991 in words is "twenty-five million, eight hundred eighty-six thousand, nine hundred ninety-one".