21212221021073 has 2 divisors, whose sum is σ = 21212221021074. Its totient is φ = 21212221021072.

The previous prime is 21212221021067. The next prime is 21212221021093. The reversal of 21212221021073 is 37012012221212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14799232038529 + 6412988982544 = 3846977^2 + 2532388^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212221021073 - 2⁶ = 21212221021009 is a prime.

It is not a weakly prime, because it can be changed into another prime (21212221021093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606110510536 + 10606110510537.

It is an arithmetic number, because the mean of its divisors is an integer number (10606110510537).

Almost surely, 2^{21212221021073} is an apocalyptic number.

It is an amenable number.

21212221021073 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212221021073 is an equidigital number, since it uses as much as digits as its factorization.

21212221021073 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1344, while the sum is 26.

Adding to 21212221021073 its reverse (37012012221212), we get a palindrome (58224233242285).

The spelling of 21212221021073 in words is "twenty-one trillion, two hundred twelve billion, two hundred twenty-one million, twenty-one thousand, seventy-three".