20233121221 has 2 divisors, whose sum is σ = 20233121222. Its totient is φ = 20233121220.

The previous prime is 20233121219. The next prime is 20233121267. The reversal of 20233121221 is 12212133202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20231933121 + 1188100 = 142239^2 + 1090^2 .

It is a cyclic number.

It is not a de Polignac number, because 20233121221 - 2¹ = 20233121219 is a prime.

Together with 20233121219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20233121291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10116560610 + 10116560611.

It is an arithmetic number, because the mean of its divisors is an integer number (10116560611).

Almost surely, 2^20233121221 is an apocalyptic number.

It is an amenable number.

20233121221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20233121221 is an equidigital number, since it uses as much as digits as its factorization.

20233121221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 20233121221 its reverse (12212133202), we get a palindrome (32445254423).

The spelling of 20233121221 in words is "twenty billion, two hundred thirty-three million, one hundred twenty-one thousand, two hundred twenty-one".