211021121021 has 2 divisors, whose sum is σ = 211021121022. Its totient is φ = 211021121020.

The previous prime is 211021120987. The next prime is 211021121039. The reversal of 211021121021 is 120121120112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 206310357796 + 4710763225 = 454214^2 + 68635^2 .

It is a cyclic number.

It is not a de Polignac number, because 211021121021 - 2¹⁰ = 211021119997 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 211021120987 and 211021121005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211021121071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105510560510 + 105510560511.

It is an arithmetic number, because the mean of its divisors is an integer number (105510560511).

Almost surely, 2^211021121021 is an apocalyptic number.

It is an amenable number.

211021121021 is a deficient number, since it is larger than the sum of its proper divisors (1).

211021121021 is an equidigital number, since it uses as much as digits as its factorization.

211021121021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 211021121021 its reverse (120121120112), we get a palindrome (331142241133).

Subtracting from 211021121021 its reverse (120121120112), we obtain a palindrome (90900000909).

The spelling of 211021121021 in words is "two hundred eleven billion, twenty-one million, one hundred twenty-one thousand, twenty-one".