11021211221 has 2 divisors, whose sum is σ = 11021211222. Its totient is φ = 11021211220.

The previous prime is 11021211211. The next prime is 11021211239. The reversal of 11021211221 is 12211212011.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8997471025 + 2023740196 = 94855^2 + 44986^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11021211221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11021211196 and 11021211205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11021211211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5510605610 + 5510605611.

It is an arithmetic number, because the mean of its divisors is an integer number (5510605611).

Almost surely, 2^11021211221 is an apocalyptic number.

It is an amenable number.

11021211221 is a deficient number, since it is larger than the sum of its proper divisors (1).

11021211221 is an equidigital number, since it uses as much as digits as its factorization.

11021211221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 11021211221 its reverse (12211212011), we get a palindrome (23232423232).

The spelling of 11021211221 in words is "eleven billion, twenty-one million, two hundred eleven thousand, two hundred twenty-one".