2161871 has 2 divisors, whose sum is σ = 2161872. Its totient is φ = 2161870.

The previous prime is 2161853. The next prime is 2161883. The reversal of 2161871 is 1781612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2161871 - 2¹⁴ = 2145487 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2161871.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2161571) 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 as a sum of consecutive naturals, namely, 1080935 + 1080936.

It is an arithmetic number, because the mean of its divisors is an integer number (1080936).

2^2161871 is an apocalyptic number.

2161871 is a deficient number, since it is larger than the sum of its proper divisors (1).

2161871 is an equidigital number, since it uses as much as digits as its factorization.

2161871 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 672, while the sum is 26.

The square root of 2161871 is about 1470.3302350152. The cubic root of 2161871 is about 129.3033942166.

The spelling of 2161871 in words is "two million, one hundred sixty-one thousand, eight hundred seventy-one".