2111909 has 2 divisors, whose sum is σ = 2111910. Its totient is φ = 2111908.

The previous prime is 2111897. The next prime is 2111917. The reversal of 2111909 is 9091112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2102500 + 9409 = 1450^2 + 97^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2111909 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2111939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1055954 + 1055955.

It is an arithmetic number, because the mean of its divisors is an integer number (1055955).

2^2111909 is an apocalyptic number.

It is an amenable number.

2111909 is a deficient number, since it is larger than the sum of its proper divisors (1).

2111909 is an equidigital number, since it uses as much as digits as its factorization.

2111909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 162, while the sum is 23.

The square root of 2111909 is about 1453.2408609725. The cubic root of 2111909 is about 128.2995304611.

The spelling of 2111909 in words is "two million, one hundred eleven thousand, nine hundred nine".