11555909 has 2 divisors, whose sum is σ = 11555910. Its totient is φ = 11555908.

The previous prime is 11555783. The next prime is 11555911. The reversal of 11555909 is 90955511.

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., 9746884 + 1809025 = 3122^2 + 1345^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11555909 is a prime.

It is a Sophie Germain prime.

Together with 11555911, 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 (11555969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5777954 + 5777955.

It is an arithmetic number, because the mean of its divisors is an integer number (5777955).

Almost surely, 2^11555909 is an apocalyptic number.

It is an amenable number.

11555909 is a deficient number, since it is larger than the sum of its proper divisors (1).

11555909 is an equidigital number, since it uses as much as digits as its factorization.

11555909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10125, while the sum is 35.

The square root of 11555909 is about 3399.3983291165. The cubic root of 11555909 is about 226.0830678534.

The spelling of 11555909 in words is "eleven million, five hundred fifty-five thousand, nine hundred nine".