21220221233 has 2 divisors, whose sum is σ = 21220221234. Its totient is φ = 21220221232.

The previous prime is 21220221221. The next prime is 21220221247. The reversal of 21220221233 is 33212202212.

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., 14111539264 + 7108681969 = 118792^2 + 84313^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220221233 - 2¹⁴ = 21220204849 is a prime.

It is not a weakly prime, because it can be changed into another prime (21220221203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610110616 + 10610110617.

It is an arithmetic number, because the mean of its divisors is an integer number (10610110617).

Almost surely, 2^21220221233 is an apocalyptic number.

It is an amenable number.

21220221233 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220221233 is an equidigital number, since it uses as much as digits as its factorization.

21220221233 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21220221233 its reverse (33212202212), we get a palindrome (54432423445).

The spelling of 21220221233 in words is "twenty-one billion, two hundred twenty million, two hundred twenty-one thousand, two hundred thirty-three".