25231891 has 4 divisors (see below), whose sum is σ = 25913872. Its totient is φ = 24549912.

The previous prime is 25231879. The next prime is 25231937. The reversal of 25231891 is 19813252.

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 25231891 - 2¹¹ = 25229843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25231091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 340935 + ... + 341008.

It is an arithmetic number, because the mean of its divisors is an integer number (6478468).

Almost surely, 2^25231891 is an apocalyptic number.

25231891 is a deficient number, since it is larger than the sum of its proper divisors (681981).

25231891 is an equidigital number, since it uses as much as digits as its factorization.

25231891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 681980.

The product of its digits is 4320, while the sum is 31.

The square root of 25231891 is about 5023.1355745192. The cubic root of 25231891 is about 293.3030640541.

The spelling of 25231891 in words is "twenty-five million, two hundred thirty-one thousand, eight hundred ninety-one".