11021221021 has 2 divisors, whose sum is σ = 11021221022. Its totient is φ = 11021221020.

The previous prime is 11021221009. The next prime is 11021221027. The reversal of 11021221021 is 12012212011.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8101980121 + 2919240900 = 90011^2 + 54030^2 .

It is an emirp because it is prime and its reverse (12012212011) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11021221021 - 2⁷ = 11021220893 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11021220992 and 11021221010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11021221027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5510610510 + 5510610511.

It is an arithmetic number, because the mean of its divisors is an integer number (5510610511).

Almost surely, 2^11021221021 is an apocalyptic number.

It is an amenable number.

11021221021 is a deficient number, since it is larger than the sum of its proper divisors (1).

11021221021 is an equidigital number, since it uses as much as digits as its factorization.

11021221021 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 13.

Adding to 11021221021 its reverse (12012212011), we get a palindrome (23033433032).

The spelling of 11021221021 in words is "eleven billion, twenty-one million, two hundred twenty-one thousand, twenty-one".