211121021 has 2 divisors, whose sum is σ = 211121022. Its totient is φ = 211121020.

The previous prime is 211121003. The next prime is 211121047. The reversal of 211121021 is 120121112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 211120900 + 121 = 14530^2 + 11^2 .

It is a cyclic number.

It is not a de Polignac number, because 211121021 - 2²² = 206926717 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 211120993 and 211121011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211121051) 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, 105560510 + 105560511.

It is an arithmetic number, because the mean of its divisors is an integer number (105560511).

Almost surely, 2^211121021 is an apocalyptic number.

It is an amenable number.

211121021 is a deficient number, since it is larger than the sum of its proper divisors (1).

211121021 is an equidigital number, since it uses as much as digits as its factorization.

211121021 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 11.

The square root of 211121021 is about 14530.0041637984. The cubic root of 211121021 is about 595.4479793672.

Adding to 211121021 its reverse (120121112), we get a palindrome (331242133).

Subtracting from 211121021 its reverse (120121112), we obtain a palindrome (90999909).

It can be divided in two parts, 2111 and 21021, that added together give a palindrome (23132).

The spelling of 211121021 in words is "two hundred eleven million, one hundred twenty-one thousand, twenty-one".