11220021221 has 4 divisors (see below), whose sum is σ = 11221028844. Its totient is φ = 11219013600.

The previous prime is 11220021217. The next prime is 11220021223. The reversal of 11220021221 is 12212002211.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12212002211 = 32507 ⋅375673.

It can be written as a sum of positive squares in 2 ways, for example, as 9386896996 + 1833124225 = 96886^2 + 42815^2 .

It is a cyclic number.

It is not a de Polignac number, because 11220021221 - 2² = 11220021217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11220021196 and 11220021205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11220021223) 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, 486920 + ... + 509441.

It is an arithmetic number, because the mean of its divisors is an integer number (2805257211).

Almost surely, 2^11220021221 is an apocalyptic number.

It is an amenable number.

11220021221 is a deficient number, since it is larger than the sum of its proper divisors (1007623).

11220021221 is an equidigital number, since it uses as much as digits as its factorization.

11220021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1007622.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 11220021221 its reverse (12212002211), we get a palindrome (23432023432).

The spelling of 11220021221 in words is "eleven billion, two hundred twenty million, twenty-one thousand, two hundred twenty-one".