11021111221 has 2 divisors, whose sum is σ = 11021111222. Its totient is φ = 11021111220.

The previous prime is 11021111207. The next prime is 11021111261. The reversal of 11021111221 is 12211112011.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10877447025 + 143664196 = 104295^2 + 11986^2 .

It is a cyclic number.

It is not a de Polignac number, because 11021111221 - 2¹⁷ = 11020980149 is a prime.

It is a super-2 number, since 2×11021111221² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11021111201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5510555610 + 5510555611.

It is an arithmetic number, because the mean of its divisors is an integer number (5510555611).

Almost surely, 2^11021111221 is an apocalyptic number.

It is an amenable number.

11021111221 is a deficient number, since it is larger than the sum of its proper divisors (1).

11021111221 is an equidigital number, since it uses as much as digits as its factorization.

11021111221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 11021111221 its reverse (12211112011), we get a palindrome (23232223232).

The spelling of 11021111221 in words is "eleven billion, twenty-one million, one hundred eleven thousand, two hundred twenty-one".