11809121 has 4 divisors (see below), whose sum is σ = 11825172. Its totient is φ = 11793072.

The previous prime is 11809111. The next prime is 11809141. The reversal of 11809121 is 12190811.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12190811 = 269 ⋅45319.

It can be written as a sum of positive squares in 2 ways, for example, as 846400 + 10962721 = 920^2 + 3311^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11809121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11809111) 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, 6866 + ... + 8411.

It is an arithmetic number, because the mean of its divisors is an integer number (2956293).

Almost surely, 2^11809121 is an apocalyptic number.

It is an amenable number.

11809121 is a deficient number, since it is larger than the sum of its proper divisors (16051).

11809121 is an equidigital number, since it uses as much as digits as its factorization.

11809121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16050.

The product of its (nonzero) digits is 144, while the sum is 23.

The square root of 11809121 is about 3436.4401638905. The cubic root of 11809121 is about 227.7224551919.

Adding to 11809121 its reverse (12190811), we get a palindrome (23999932).

It can be divided in two parts, 1180 and 9121, that added together give a palindrome (10301).

The spelling of 11809121 in words is "eleven million, eight hundred nine thousand, one hundred twenty-one".