211121012020021 has 2 divisors, whose sum is σ = 211121012020022. Its totient is φ = 211121012020020.

The previous prime is 211121012020013. The next prime is 211121012020103. The reversal of 211121012020021 is 120020210121112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 176087220485796 + 35033791534225 = 13269786^2 + 5918935^2 .

It is a cyclic number.

It is not a de Polignac number, because 211121012020021 - 2³ = 211121012020013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 211121012019977 and 211121012020004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211121012020421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105560506010010 + 105560506010011.

It is an arithmetic number, because the mean of its divisors is an integer number (105560506010011).

Almost surely, 2^{211121012020021} is an apocalyptic number.

It is an amenable number.

211121012020021 is a deficient number, since it is larger than the sum of its proper divisors (1).

211121012020021 is an equidigital number, since it uses as much as digits as its factorization.

211121012020021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 211121012020021 its reverse (120020210121112), we get a palindrome (331141222141133).

The spelling of 211121012020021 in words is "two hundred eleven trillion, one hundred twenty-one billion, twelve million, twenty thousand, twenty-one".