20211111211 has 2 divisors, whose sum is σ = 20211111212. Its totient is φ = 20211111210.

The previous prime is 20211111203. The next prime is 20211111247. The reversal of 20211111211 is 11211111202.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20211111211 - 2³ = 20211111203 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20211111191 and 20211111200.

It is not a weakly prime, because it can be changed into another prime (20211111511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105555605 + 10105555606.

It is an arithmetic number, because the mean of its divisors is an integer number (10105555606).

Almost surely, 2^20211111211 is an apocalyptic number.

20211111211 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211111211 is an equidigital number, since it uses as much as digits as its factorization.

20211111211 is an odious number, because the sum of its binary digits is odd.

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

Adding to 20211111211 its reverse (11211111202), we get a palindrome (31422222413).

Subtracting from 20211111211 its reverse (11211111202), we obtain a palindrome (9000000009).

The spelling of 20211111211 in words is "twenty billion, two hundred eleven million, one hundred eleven thousand, two hundred eleven".