20123223121 has 2 divisors, whose sum is σ = 20123223122. Its totient is φ = 20123223120.

The previous prime is 20123223077. The next prime is 20123223151. The reversal of 20123223121 is 12132232102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19482576400 + 640646721 = 139580^2 + 25311^2 .

It is a cyclic number.

It is not a de Polignac number, because 20123223121 - 2⁷ = 20123222993 is a prime.

It is not a weakly prime, because it can be changed into another prime (20123223151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10061611560 + 10061611561.

It is an arithmetic number, because the mean of its divisors is an integer number (10061611561).

Almost surely, 2^20123223121 is an apocalyptic number.

It is an amenable number.

20123223121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20123223121 is an equidigital number, since it uses as much as digits as its factorization.

20123223121 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 20123223121 its reverse (12132232102), we get a palindrome (32255455223).

The spelling of 20123223121 in words is "twenty billion, one hundred twenty-three million, two hundred twenty-three thousand, one hundred twenty-one".