212111020021 has 2 divisors, whose sum is σ = 212111020022. Its totient is φ = 212111020020.

The previous prime is 212111020013. The next prime is 212111020063. The reversal of 212111020021 is 120020111212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 137704819396 + 74406200625 = 371086^2 + 272775^2 .

It is a cyclic number.

It is not a de Polignac number, because 212111020021 - 2³ = 212111020013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 212111019983 and 212111020010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212111020621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106055510010 + 106055510011.

It is an arithmetic number, because the mean of its divisors is an integer number (106055510011).

Almost surely, 2^212111020021 is an apocalyptic number.

It is an amenable number.

212111020021 is a deficient number, since it is larger than the sum of its proper divisors (1).

212111020021 is an equidigital number, since it uses as much as digits as its factorization.

212111020021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 212111020021 its reverse (120020111212), we get a palindrome (332131131233).

The spelling of 212111020021 in words is "two hundred twelve billion, one hundred eleven million, twenty thousand, twenty-one".