11009921 has 4 divisors (see below), whose sum is σ = 11856852. Its totient is φ = 10162992.

The previous prime is 11009881. The next prime is 11009927. The reversal of 11009921 is 12990011.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4456321 + 6553600 = 2111^2 + 2560^2 .

It is a cyclic number.

It is not a de Polignac number, because 11009921 - 2¹⁰ = 11008897 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (11009927) 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, 423446 + ... + 423471.

It is an arithmetic number, because the mean of its divisors is an integer number (2964213).

Almost surely, 2^11009921 is an apocalyptic number.

It is an amenable number.

11009921 is a deficient number, since it is larger than the sum of its proper divisors (846931).

11009921 is an equidigital number, since it uses as much as digits as its factorization.

11009921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 846930.

The product of its (nonzero) digits is 162, while the sum is 23.

The square root of 11009921 is about 3318.1201002978. The cubic root of 11009921 is about 222.4648498949.

Adding to 11009921 its reverse (12990011), we get a palindrome (23999932).

The spelling of 11009921 in words is "eleven million, nine thousand, nine hundred twenty-one".