211111300021 has 2 divisors, whose sum is σ = 211111300022. Its totient is φ = 211111300020.

The previous prime is 211111300019. The next prime is 211111300033. The reversal of 211111300021 is 120003111112.

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., 179822643025 + 31288656996 = 424055^2 + 176886^2 .

It is a cyclic number.

It is not a de Polignac number, because 211111300021 - 2¹ = 211111300019 is a prime.

Together with 211111300019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 211111299974 and 211111300010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211117300021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105555650010 + 105555650011.

It is an arithmetic number, because the mean of its divisors is an integer number (105555650011).

Almost surely, 2^211111300021 is an apocalyptic number.

It is an amenable number.

211111300021 is a deficient number, since it is larger than the sum of its proper divisors (1).

211111300021 is an equidigital number, since it uses as much as digits as its factorization.

211111300021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12, while the sum is 13.

Adding to 211111300021 its reverse (120003111112), we get a palindrome (331114411133).

The spelling of 211111300021 in words is "two hundred eleven billion, one hundred eleven million, three hundred thousand, twenty-one".