4091909 has 2 divisors, whose sum is σ = 4091910. Its totient is φ = 4091908.

The previous prime is 4091873. The next prime is 4091911. The reversal of 4091909 is 9091904.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4060225 + 31684 = 2015^2 + 178^2 .

It is a cyclic number.

It is not a de Polignac number, because 4091909 - 2²⁰ = 3043333 is a prime.

Together with 4091911, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4091959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2045954 + 2045955.

It is an arithmetic number, because the mean of its divisors is an integer number (2045955).

Almost surely, 2^4091909 is an apocalyptic number.

It is an amenable number.

4091909 is a deficient number, since it is larger than the sum of its proper divisors (1).

4091909 is an equidigital number, since it uses as much as digits as its factorization.

4091909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2916, while the sum is 32.

The square root of 4091909 is about 2022.8467564302. The cubic root of 4091909 is about 159.9467140266.

The spelling of 4091909 in words is "four million, ninety-one thousand, nine hundred nine".