11171531909 has 2 divisors, whose sum is σ = 11171531910. Its totient is φ = 11171531908.

The previous prime is 11171531863. The next prime is 11171531911. The reversal of 11171531909 is 90913517111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11137636225 + 33895684 = 105535^2 + 5822^2 .

It is a cyclic number.

It is not a de Polignac number, because 11171531909 - 2⁸ = 11171531653 is a prime.

It is a Sophie Germain prime.

Together with 11171531911, 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 (11171531009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5585765954 + 5585765955.

It is an arithmetic number, because the mean of its divisors is an integer number (5585765955).

Almost surely, 2^11171531909 is an apocalyptic number.

It is an amenable number.

11171531909 is a deficient number, since it is larger than the sum of its proper divisors (1).

11171531909 is an equidigital number, since it uses as much as digits as its factorization.

11171531909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8505, while the sum is 38.

The spelling of 11171531909 in words is "eleven billion, one hundred seventy-one million, five hundred thirty-one thousand, nine hundred nine".