1909109 has 2 divisors, whose sum is σ = 1909110. Its totient is φ = 1909108.

The previous prime is 1909091. The next prime is 1909111. The reversal of 1909109 is 9019091.

Together with previous prime (1909091) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1575025 + 334084 = 1255^2 + 578^2 .

It is a cyclic number.

It is not a de Polignac number, because 1909109 - 2²⁰ = 860533 is a prime.

It is a Sophie Germain prime.

Together with 1909111, 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 (1909129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 954554 + 954555.

It is an arithmetic number, because the mean of its divisors is an integer number (954555).

2^1909109 is an apocalyptic number.

It is an amenable number.

1909109 is a deficient number, since it is larger than the sum of its proper divisors (1).

1909109 is an equidigital number, since it uses as much as digits as its factorization.

1909109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 729, while the sum is 29.

The square root of 1909109 is about 1381.7051060194. The cubic root of 1909109 is about 124.0538484472.

The spelling of 1909109 in words is "one million, nine hundred nine thousand, one hundred nine".