21233220230021 has 2 divisors, whose sum is σ = 21233220230022. Its totient is φ = 21233220230020.

The previous prime is 21233220229997. The next prime is 21233220230099. The reversal of 21233220230021 is 12003202233212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16713828945025 + 4519391284996 = 4088255^2 + 2125886^2 .

It is a cyclic number.

It is not a de Polignac number, because 21233220230021 - 2¹⁴ = 21233220213637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21233220230921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10616610115010 + 10616610115011.

It is an arithmetic number, because the mean of its divisors is an integer number (10616610115011).

Almost surely, 2^{21233220230021} is an apocalyptic number.

It is an amenable number.

21233220230021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21233220230021 is an equidigital number, since it uses as much as digits as its factorization.

21233220230021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 23.

Adding to 21233220230021 its reverse (12003202233212), we get a palindrome (33236422463233).

The spelling of 21233220230021 in words is "twenty-one trillion, two hundred thirty-three billion, two hundred twenty million, two hundred thirty thousand, twenty-one".