11691909 has 6 divisors (see below), whose sum is σ = 16888326. Its totient is φ = 7794600.

The previous prime is 11691907. The next prime is 11691917. The reversal of 11691909 is 90919611.

11691909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 11492100 + 199809 = 3390^2 + 447^2 .

It is not a de Polignac number, because 11691909 - 2¹ = 11691907 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11691907) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 649542 + ... + 649559.

It is an arithmetic number, because the mean of its divisors is an integer number (2814721).

Almost surely, 2^11691909 is an apocalyptic number.

It is an amenable number.

11691909 is a deficient number, since it is larger than the sum of its proper divisors (5196417).

11691909 is a wasteful number, since it uses less digits than its factorization.

11691909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1299107 (or 1299104 counting only the distinct ones).

The product of its (nonzero) digits is 4374, while the sum is 36.

The square root of 11691909 is about 3419.3433580148. The cubic root of 11691909 is about 226.9665252378.

The spelling of 11691909 in words is "eleven million, six hundred ninety-one thousand, nine hundred nine".