2891891 has 2 divisors, whose sum is σ = 2891892. Its totient is φ = 2891890.

The previous prime is 2891831. The next prime is 2891893. The reversal of 2891891 is 1981982.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2891891 is a prime.

Together with 2891893, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2891893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1445945 + 1445946.

It is an arithmetic number, because the mean of its divisors is an integer number (1445946).

2^2891891 is an apocalyptic number.

2891891 is a deficient number, since it is larger than the sum of its proper divisors (1).

2891891 is an equidigital number, since it uses as much as digits as its factorization.

2891891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 38.

The square root of 2891891 is about 1700.5560855203. The cubic root of 2891891 is about 142.4712735775.

Subtracting from 2891891 its reverse (1981982), we obtain a palindrome (909909).

It can be divided in two parts, 28 and 91891, that added together give a palindrome (91919).

The spelling of 2891891 in words is "two million, eight hundred ninety-one thousand, eight hundred ninety-one".