2111309 has 2 divisors, whose sum is σ = 2111310. Its totient is φ = 2111308.

The previous prime is 2111303. The next prime is 2111311. The reversal of 2111309 is 9031112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2111209 + 100 = 1453^2 + 10^2 .

It is a cyclic number.

It is not a de Polignac number, because 2111309 - 2¹⁶ = 2045773 is a prime.

It is a Sophie Germain prime.

Together with 2111311, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2111303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1055654 + 1055655.

It is an arithmetic number, because the mean of its divisors is an integer number (1055655).

2^2111309 is an apocalyptic number.

It is an amenable number.

2111309 is a deficient number, since it is larger than the sum of its proper divisors (1).

2111309 is an equidigital number, since it uses as much as digits as its factorization.

2111309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54, while the sum is 17.

The square root of 2111309 is about 1453.0344111548. The cubic root of 2111309 is about 128.2873792100.

The spelling of 2111309 in words is "two million, one hundred eleven thousand, three hundred nine".