23231321021 has 2 divisors, whose sum is σ = 23231321022. Its totient is φ = 23231321020.

The previous prime is 23231320991. The next prime is 23231321039. The reversal of 23231321021 is 12012313232.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23017137796 + 214183225 = 151714^2 + 14635^2 .

It is a cyclic number.

It is not a de Polignac number, because 23231321021 - 2¹⁴ = 23231304637 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 23231320984 and 23231321002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23231321081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11615660510 + 11615660511.

It is an arithmetic number, because the mean of its divisors is an integer number (11615660511).

Almost surely, 2^23231321021 is an apocalyptic number.

It is an amenable number.

23231321021 is a deficient number, since it is larger than the sum of its proper divisors (1).

23231321021 is an equidigital number, since it uses as much as digits as its factorization.

23231321021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 23231321021 its reverse (12012313232), we get a palindrome (35243634253).

The spelling of 23231321021 in words is "twenty-three billion, two hundred thirty-one million, three hundred twenty-one thousand, twenty-one".