11820909 has 4 divisors (see below), whose sum is σ = 15761216. Its totient is φ = 7880604.

The previous prime is 11820901. The next prime is 11820947. The reversal of 11820909 is 90902811.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 90902811 = 3 ⋅30300937.

It is not a de Polignac number, because 11820909 - 2³ = 11820901 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11820901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1970149 + ... + 1970154.

It is an arithmetic number, because the mean of its divisors is an integer number (3940304).

Almost surely, 2^11820909 is an apocalyptic number.

It is an amenable number.

11820909 is a deficient number, since it is larger than the sum of its proper divisors (3940307).

11820909 is an equidigital number, since it uses as much as digits as its factorization.

11820909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3940306.

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 11820909 is about 3438.1548830732. The cubic root of 11820909 is about 227.7982017159.

The spelling of 11820909 in words is "eleven million, eight hundred twenty thousand, nine hundred nine".