11105821 has 4 divisors (see below), whose sum is σ = 11220412. Its totient is φ = 10991232.

The previous prime is 11105807. The next prime is 11105827. The reversal of 11105821 is 12850111.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12850111 = 211 ⋅60901.

It can be written as a sum of positive squares in 2 ways, for example, as 3204100 + 7901721 = 1790^2 + 2811^2 .

It is a cyclic number.

It is not a de Polignac number, because 11105821 - 2⁵ = 11105789 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 (11105827) 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 in 3 ways as a sum of consecutive naturals, for example, 57150 + ... + 57343.

It is an arithmetic number, because the mean of its divisors is an integer number (2805103).

Almost surely, 2^11105821 is an apocalyptic number.

It is an amenable number.

11105821 is a deficient number, since it is larger than the sum of its proper divisors (114591).

11105821 is an equidigital number, since it uses as much as digits as its factorization.

11105821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114590.

The product of its (nonzero) digits is 80, while the sum is 19.

The square root of 11105821 is about 3332.5397221939. The cubic root of 11105821 is about 223.1088973254.

Adding to 11105821 its reverse (12850111), we get a palindrome (23955932).

The spelling of 11105821 in words is "eleven million, one hundred five thousand, eight hundred twenty-one".