11121211021 has 2 divisors, whose sum is σ = 11121211022. Its totient is φ = 11121211020.

The previous prime is 11121211019. The next prime is 11121211037. The reversal of 11121211021 is 12011212111.

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., 5896089796 + 5225121225 = 76786^2 + 72285^2 .

It is a cyclic number.

It is not a de Polignac number, because 11121211021 - 2¹ = 11121211019 is a prime.

It is a super-2 number, since 2×11121211021² (a number of 21 digits) contains 22 as substring.

Together with 11121211019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 11121210992 and 11121211010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11121211121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5560605510 + 5560605511.

It is an arithmetic number, because the mean of its divisors is an integer number (5560605511).

Almost surely, 2^11121211021 is an apocalyptic number.

It is an amenable number.

11121211021 is a deficient number, since it is larger than the sum of its proper divisors (1).

11121211021 is an equidigital number, since it uses as much as digits as its factorization.

11121211021 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 11121211021 its reverse (12011212111), we get a palindrome (23132423132).

The spelling of 11121211021 in words is "eleven billion, one hundred twenty-one million, two hundred eleven thousand, twenty-one".