25931891 has 4 divisors (see below), whose sum is σ = 25990872. Its totient is φ = 25872912.

The previous prime is 25931861. The next prime is 25931897. The reversal of 25931891 is 19813952.

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

It is a cyclic number.

It is not a de Polignac number, because 25931891 - 2¹⁸ = 25669747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25931897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28826 + ... + 29711.

It is an arithmetic number, because the mean of its divisors is an integer number (6497718).

Almost surely, 2^25931891 is an apocalyptic number.

25931891 is a deficient number, since it is larger than the sum of its proper divisors (58981).

25931891 is an equidigital number, since it uses as much as digits as its factorization.

25931891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58980.

The product of its digits is 19440, while the sum is 38.

The square root of 25931891 is about 5092.3364971298. The cubic root of 25931891 is about 295.9906977537.

The spelling of 25931891 in words is "twenty-five million, nine hundred thirty-one thousand, eight hundred ninety-one".