25208991 has 18 divisors (see below), whose sum is σ = 38435280. Its totient is φ = 15919416.

The previous prime is 25208987. The next prime is 25208993. The reversal of 25208991 is 19980252.

It is not a de Polignac number, because 25208991 - 2² = 25208987 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25208993) 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 17 ways as a sum of consecutive naturals, for example, 631 + ... + 7128.

Almost surely, 2^25208991 is an apocalyptic number.

25208991 is a deficient number, since it is larger than the sum of its proper divisors (13226289).

25208991 is a wasteful number, since it uses less digits than its factorization.

25208991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7803 (or 7781 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 25208991 is about 5020.8556043766. The cubic root of 25208991 is about 293.2143050419.

It can be divided in two parts, 2520 and 8991, that added together give a palindrome (11511).

The spelling of 25208991 in words is "twenty-five million, two hundred eight thousand, nine hundred ninety-one".