25891491 has 16 divisors (see below), whose sum is σ = 36158976. Its totient is φ = 16448256.

The previous prime is 25891487. The next prime is 25891543. The reversal of 25891491 is 19419852.

It is not a de Polignac number, because 25891491 - 2² = 25891487 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25891441) 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 15 ways as a sum of consecutive naturals, for example, 23826 + ... + 24888.

It is an arithmetic number, because the mean of its divisors is an integer number (2259936).

Almost surely, 2^25891491 is an apocalyptic number.

25891491 is a deficient number, since it is larger than the sum of its proper divisors (10267485).

25891491 is a wasteful number, since it uses less digits than its factorization.

25891491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1442.

The product of its digits is 25920, while the sum is 39.

The square root of 25891491 is about 5088.3682060165. The cubic root of 25891491 is about 295.8369072019.

The spelling of 25891491 in words is "twenty-five million, eight hundred ninety-one thousand, four hundred ninety-one".