25131891 has 4 divisors (see below), whose sum is σ = 33509192. Its totient is φ = 16754592.

The previous prime is 25131871. The next prime is 25131913. The reversal of 25131891 is 19813152.

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

It is not a de Polignac number, because 25131891 - 2⁵ = 25131859 is a prime.

It is a super-2 number, since 2×25131891² = 1263223890471762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25131871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4188646 + ... + 4188651.

It is an arithmetic number, because the mean of its divisors is an integer number (8377298).

Almost surely, 2^25131891 is an apocalyptic number.

25131891 is a deficient number, since it is larger than the sum of its proper divisors (8377301).

25131891 is an equidigital number, since it uses as much as digits as its factorization.

25131891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8377300.

The product of its digits is 2160, while the sum is 30.

The square root of 25131891 is about 5013.1717504989. The cubic root of 25131891 is about 292.9150743785.

The spelling of 25131891 in words is "twenty-five million, one hundred thirty-one thousand, eight hundred ninety-one".