2051891 has 2 divisors, whose sum is σ = 2051892. Its totient is φ = 2051890.

The previous prime is 2051887. The next prime is 2051893. The reversal of 2051891 is 1981502.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2051891 - 2² = 2051887 is a prime.

Together with 2051893, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2051891.

It is not a weakly prime, because it can be changed into another prime (2051893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1025945 + 1025946.

It is an arithmetic number, because the mean of its divisors is an integer number (1025946).

2^2051891 is an apocalyptic number.

2051891 is a deficient number, since it is larger than the sum of its proper divisors (1).

2051891 is an equidigital number, since it uses as much as digits as its factorization.

2051891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 26.

The square root of 2051891 is about 1432.4423199557. The cubic root of 2051891 is about 127.0724574646.

The spelling of 2051891 in words is "two million, fifty-one thousand, eight hundred ninety-one".