21212200111021 has 2 divisors, whose sum is σ = 21212200111022. Its totient is φ = 21212200111020.

The previous prime is 21212200111013. The next prime is 21212200111031. The reversal of 21212200111021 is 12011100221212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20622815325225 + 589384785796 = 4541235^2 + 767714^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212200111021 - 2³ = 21212200111013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21212200110986 and 21212200111004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21212200111031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606100055510 + 10606100055511.

It is an arithmetic number, because the mean of its divisors is an integer number (10606100055511).

Almost surely, 2^{21212200111021} is an apocalyptic number.

It is an amenable number.

21212200111021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212200111021 is an equidigital number, since it uses as much as digits as its factorization.

21212200111021 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 21212200111021 its reverse (12011100221212), we get a palindrome (33223300332233).

The spelling of 21212200111021 in words is "twenty-one trillion, two hundred twelve billion, two hundred million, one hundred eleven thousand, twenty-one".